diff --git a/api.planx.uk/docs/index.ts b/api.planx.uk/docs/index.ts
index f12939a0b6..734fb58606 100644
--- a/api.planx.uk/docs/index.ts
+++ b/api.planx.uk/docs/index.ts
@@ -36,7 +36,7 @@ const parameters = {
     type: "string",
     required: true,
     description:
-      "Name of the Local Authority, usually the same as Planx `team`",
+      "Name of the Local Authority, usually the same as PlanX `team`",
   },
   hasuraAuth: {
     name: "authorization",
diff --git a/api.planx.uk/inviteToPay/inviteToPay.ts b/api.planx.uk/inviteToPay/inviteToPay.ts
deleted file mode 100644
index 6dfa87267e..0000000000
--- a/api.planx.uk/inviteToPay/inviteToPay.ts
+++ /dev/null
@@ -1,89 +0,0 @@
-import { NextFunction, Request, Response } from "express";
-import type { PaymentRequest, KeyPath } from "@opensystemslab/planx-core/types";
-
-import { ServerError } from "../errors";
-import { $api } from "../client";
-
-export async function inviteToPay(
-  req: Request,
-  res: Response,
-  next: NextFunction,
-) {
-  const sessionId = req.params.sessionId;
-  const {
-    payeeEmail,
-    payeeName,
-    applicantName,
-    sessionPreviewKeys,
-  }: {
-    payeeEmail: string;
-    payeeName: string;
-    applicantName: string;
-    sessionPreviewKeys: Array<KeyPath>;
-  } = req.body;
-
-  for (const [requiredFieldName, requiredFieldValue] of Object.entries({
-    sessionId,
-    applicantName,
-    payeeName,
-    payeeEmail,
-  })) {
-    if (!requiredFieldValue) {
-      return next(
-        new ServerError({
-          message: `JSON body must contain ${requiredFieldName}`,
-          status: 400,
-        }),
-      );
-    }
-  }
-
-  // lock session before creating a payment request
-  const locked = await $api.session.lock(sessionId);
-  if (locked === null) {
-    return next(
-      new ServerError({
-        message: "session not found",
-        status: 404,
-      }),
-    );
-  }
-  if (locked === false) {
-    const cause = new Error(
-      "this session could not be locked, perhaps because it is already locked",
-    );
-    return next(
-      new ServerError({
-        message: `could not initiate a payment request: ${cause.message}`,
-        status: 400,
-        cause,
-      }),
-    );
-  }
-
-  let paymentRequest: PaymentRequest | undefined;
-  try {
-    paymentRequest = await $api.paymentRequest.create({
-      sessionId,
-      applicantName,
-      payeeName,
-      payeeEmail,
-      sessionPreviewKeys,
-    });
-  } catch (e: unknown) {
-    // revert the session lock on failure
-    await $api.session.unlock(sessionId);
-    return next(
-      new ServerError({
-        message:
-          e instanceof Error
-            ? `could not initiate a payment request: ${e.message}`
-            : "could not initiate a payment request due to an unknown error",
-        status: 500,
-        cause: e,
-      }),
-    );
-  }
-
-  res.json(paymentRequest);
-}
diff --git a/api.planx.uk/pay/index.ts b/api.planx.uk/modules/pay/controller.ts
similarity index 57%
rename from api.planx.uk/pay/index.ts
rename to api.planx.uk/modules/pay/controller.ts
index 0e525c3e04..8d2fe4bfb4 100644
--- a/api.planx.uk/pay/index.ts
+++ b/api.planx.uk/modules/pay/controller.ts
@@ -1,48 +1,32 @@
 import assert from "assert";
-import { NextFunction, Request, Response } from "express";
+import { Request } from "express";
 import { responseInterceptor } from "http-proxy-middleware";
-import SlackNotify from "slack-notify";
-import { logPaymentStatus } from "../send/helpers";
+import { logPaymentStatus } from "../../send/helpers";
 import { usePayProxy } from "./proxy";
-import { $api } from "../client";
-import { ServerError } from "../errors";
-import { GovUKPayment } from "@opensystemslab/planx-core/types";
-import { addGovPayPaymentIdToPaymentRequest } from "./utils";
+import { $api } from "../../client";
+import { ServerError } from "../../errors";
+import { GovUKPayment, PaymentRequest } from "@opensystemslab/planx-core/types";
+import {
+  addGovPayPaymentIdToPaymentRequest,
+  postPaymentNotificationToSlack,
+} from "./service/utils";
+import {
+  InviteToPayController,
+  PaymentProxyController,
+  PaymentRequestProxyController,
+} from "./types";
 
 assert(process.env.SLACK_WEBHOOK_URL);
 
 // exposed as /pay/:localAuthority and also used as middleware
 // returns the url to make a gov uk payment
-export async function makePaymentViaProxy(
-  req: Request,
-  res: Response,
-  next: NextFunction,
-) {
-  // confirm that this local authority (aka team) has a pay token configured before creating the proxy
-  const isSupported =
-    process.env[`GOV_UK_PAY_TOKEN_${req.params.localAuthority.toUpperCase()}`];
-
-  if (!isSupported) {
-    return next(
-      new ServerError({
-        message: `GOV.UK Pay is not enabled for this local authority (${req.params.localAuthority})`,
-        status: 400,
-      }),
-    );
-  }
-
-  const flowId = req.query?.flowId as string | undefined;
-  const sessionId = req.query?.sessionId as string | undefined;
-  const teamSlug = req.params.localAuthority;
-
-  if (!flowId || !sessionId || !teamSlug) {
-    return next(
-      new ServerError({
-        message: "Missing required query param",
-        status: 400,
-      }),
-    );
-  }
+export const makePaymentViaProxy: PaymentProxyController = async (
+  req,
+  res,
+  next,
+) => {
+  const { flowId, sessionId } = res.locals.parsedReq.query;
+  const teamSlug = res.locals.parsedReq.params.localAuthority;
 
   const session = await $api.session.findDetails(sessionId);
 
@@ -77,28 +61,16 @@ export async function makePaymentViaProxy(
     },
     req,
   )(req, res, next);
-}
+};
 
-export async function makeInviteToPayPaymentViaProxy(
-  req: Request,
-  res: Response,
-  next: NextFunction,
-) {
-  // confirm that this local authority (aka team) has a pay token configured before creating the proxy
-  const isSupported =
-    process.env[`GOV_UK_PAY_TOKEN_${req.params.localAuthority.toUpperCase()}`];
-
-  if (!isSupported) {
-    return next({
-      status: 400,
-      message: `GOV.UK Pay is not enabled for this local authority (${req.params.localAuthority})`,
-    });
-  }
-
-  const flowId = req.query?.flowId as string | undefined;
-  const sessionId = req.query?.sessionId as string | undefined;
-  const paymentRequestId = req.params?.paymentRequest as string;
-  const teamSlug = req.params.localAuthority;
+export const makeInviteToPayPaymentViaProxy: PaymentRequestProxyController = (
+  req,
+  res,
+  next,
+) => {
+  const { flowId, sessionId } = res.locals.parsedReq.query;
+  const { localAuthority: teamSlug, paymentRequest: paymentRequestId } =
+    res.locals.parsedReq.params;
 
   // drop req.params.localAuthority from the path when redirecting
   // so redirects to plain [GOV_UK_PAY_URL] with correct bearer token
@@ -130,7 +102,7 @@ export async function makeInviteToPayPaymentViaProxy(
     },
     req,
   )(req, res, next);
-}
+};
 
 // exposed as /pay/:localAuthority/:paymentId and also used as middleware
 // fetches the status of the payment
@@ -141,11 +113,10 @@ export const fetchPaymentViaProxy = fetchPaymentViaProxyWithCallback(
 
 export function fetchPaymentViaProxyWithCallback(
   callback: (req: Request, govUkPayment: GovUKPayment) => Promise<void>,
-) {
-  return async (req: Request, res: Response, next: NextFunction) => {
-    const flowId = req.query?.flowId as string | undefined;
-    const sessionId = req.query?.sessionId as string | undefined;
-    const teamSlug = req.params.localAuthority;
+): PaymentProxyController {
+  return async (req, res, next) => {
+    const { flowId, sessionId } = res.locals.parsedReq.query;
+    const teamSlug = res.locals.parsedReq.params.localAuthority;
 
     // will redirect to [GOV_UK_PAY_URL]/:paymentId with correct bearer token
     usePayProxy(
@@ -184,22 +155,56 @@ export function fetchPaymentViaProxyWithCallback(
   };
 }
 
-export async function postPaymentNotificationToSlack(
-  req: Request,
-  govUkResponse: GovUKPayment,
-  label = "",
-) {
-  // if it's a prod payment, notify #planx-notifications so we can monitor for subsequent submissions
-  if (govUkResponse?.payment_provider !== "sandbox") {
-    const slack = SlackNotify(process.env.SLACK_WEBHOOK_URL!);
-    const getStatus = (state: GovUKPayment["state"]) =>
-      state.status + (state.message ? ` (${state.message})` : "");
-    const payMessage = `:coin: New GOV Pay payment ${label} *${
-      govUkResponse.payment_id
-    }* with status *${getStatus(govUkResponse.state)}* [${
-      req.params.localAuthority
-    }]`;
-    await slack.send(payMessage);
-    console.log("Payment notification posted to Slack");
+export const inviteToPay: InviteToPayController = async (_req, res, next) => {
+  const { sessionId } = res.locals.parsedReq.params;
+  const { payeeEmail, payeeName, applicantName, sessionPreviewKeys } =
+    res.locals.parsedReq.body;
+  // lock session before creating a payment request
+  const locked = await $api.session.lock(sessionId);
+  if (locked === null) {
+    return next(
+      new ServerError({
+        message: "session not found",
+        status: 404,
+      }),
+    );
   }
-}
+  if (locked === false) {
+    const cause = new Error(
+      "this session could not be locked, perhaps because it is already locked",
+    );
+    return next(
+      new ServerError({
+        message: `could not initiate a payment request: ${cause.message}`,
+        status: 400,
+        cause,
+      }),
+    );
+  }
+
+  let paymentRequest: PaymentRequest | undefined;
+  try {
+    paymentRequest = await $api.paymentRequest.create({
+      sessionId,
+      applicantName,
+      payeeName,
+      payeeEmail,
+      sessionPreviewKeys,
+    });
+  } catch (e: unknown) {
+    // revert the session lock on failure
+    await $api.session.unlock(sessionId);
+    return next(
+      new ServerError({
+        message:
+          e instanceof Error
+            ? `could not initiate a payment request: ${e.message}`
+            : "could not initiate a payment request due to an unknown error",
+        status: 500,
+        cause: e,
+      }),
+    );
+  }
+
+  res.json(paymentRequest);
+};
diff --git a/api.planx.uk/modules/pay/docs.yaml b/api.planx.uk/modules/pay/docs.yaml
new file mode 100644
index 0000000000..25f8a7f953
--- /dev/null
+++ b/api.planx.uk/modules/pay/docs.yaml
@@ -0,0 +1,366 @@
+openapi: 3.1.0
+info:
+  title: Plan✕ API
+  version: 0.1.0
+tags:
+  - name: pay
+    description: Endpoints for interacting with the GovPay API
+    externalDocs:
+      url: https://docs.payments.service.gov.uk/
+components:
+  parameters:
+    paymentId:
+      in: path
+      name: paymentId
+      type: string
+      format: uuid
+      required: true
+    paymentRequest:
+      in: path
+      name: paymentId
+      type: string
+      format: uuid
+      required: true
+  schemas:
+    InviteToPayRequest:
+      content:
+        application/json:
+          schema:
+            type: object
+            properties:
+              payeeEmail:
+                type: string
+                format: email
+              payeeName:
+                type: string
+              applicantName:
+                type: string
+              sessionPreviewKeys:
+                type: array
+                items:
+                  type: array
+                  items: string
+    CreatePaymentRequest:
+      description: |
+        Payment response for the GovPay API
+
+        Docs: [https://docs.payments.service.gov.uk/api_reference/single_payment_reference/#example-response-for-get-information-about-a-single-payment](https://docs.payments.service.gov.uk/api_reference/single_payment_reference/#example-response-for-get-information-about-a-single-payment)
+      content:
+        application/json:
+          schema:
+            type: object
+            properties:
+              amount:
+                type: integer
+                format: int32
+                example: 14500
+              reference:
+                type: string
+                example: "12345"
+              description:
+                type: string
+                example: "Pay your council tax"
+              return_url:
+                type: string
+                format: uri
+                example: "https://your.service.gov.uk/completed"
+              delayed_capture:
+                type: boolean
+                example: false
+              metadata:
+                type: object
+                properties:
+                  ledger_code:
+                    type: string
+                    example: "AB100"
+                  internal_reference_number:
+                    type: integer
+                    example: 200
+              email:
+                type: string
+                format: email
+                example: "sherlock.holmes@example.com"
+              prefilled_cardholder_details:
+                type: object
+                properties:
+                  cardholder_name:
+                    type: string
+                    example: "Sherlock Holmes"
+                  billing_address:
+                    type: object
+                    properties:
+                      line1:
+                        type: string
+                        example: "221 Baker Street"
+                      line2:
+                        type: string
+                        example: "Flat b"
+                      postcode:
+                        type: string
+                        example: "NW1 6XE"
+                      city:
+                        type: string
+                        example: "London"
+                      country:
+                        type: string
+                        example: "GB"
+              language:
+                type: string
+                example: "en"
+  responses:
+    CreatePaymentResponse:
+      content:
+        application/json:
+          description: |
+            Successful payment response
+
+            Docs: [https://docs.payments.service.gov.uk/api_reference/create_a_payment_reference/#example-response-for-39-create-a-payment-39](https://docs.payments.service.gov.uk/api_reference/create_a_payment_reference/#example-response-for-39-create-a-payment-39)
+          schema:
+            type: object
+            properties:
+              amount:
+                type: integer
+                format: int32
+                example: 14500
+              description:
+                type: string
+                example: "Pay your council tax."
+              reference:
+                type: string
+                example: "12345"
+              language:
+                type: string
+                example: "en"
+              state:
+                type: object
+                properties:
+                  status:
+                    type: string
+                    example: "created"
+                  finished:
+                    type: boolean
+                    example: false
+              payment_id:
+                type: string
+                example: "hu20sqlact5260q2nanm0q8u93"
+              payment_provider:
+                type: string
+                example: "stripe"
+              created_date:
+                type: string
+                format: date-time
+                example: "2022-03-25T13:11:29.019Z"
+              refund_summary:
+                type: object
+                properties:
+                  status:
+                    type: string
+                    example: "pending"
+                  amount_available:
+                    type: integer
+                    format: int32
+                    example: 14500
+                  amount_submitted:
+                    type: integer
+                    format: int32
+                    example: 0
+              settlement_summary:
+                type: object
+                properties: {}
+              delayed_capture:
+                type: boolean
+                example: false
+              moto:
+                type: boolean
+                example: false
+              return_url:
+                type: string
+                format: uri
+                example: "https://your.service.gov.uk/completed"
+              _links:
+                type: object
+                properties:
+                  self:
+                    type: object
+                    properties:
+                      href:
+                        type: string
+                        format: uri
+                        example: "https://publicapi.payments.service.gov.uk/v1/payments/hu20sqlact5260q2nanm0q8u93"
+                      method:
+                        type: string
+                        example: "GET"
+                  next_url:
+                    type: object
+                    properties:
+                      href:
+                        type: string
+                        format: uri
+                        example: "https://www.payments.service.gov.uk/secure/ef1b6ff1-db34-4c62-b854-3ed4ba3c4049"
+                      method:
+                        type: string
+                        example: "GET"
+                  next_url_post:
+                    type: object
+                    properties:
+                      type:
+                        type: string
+                        example: "application/x-www-form-urlencoded"
+                      params:
+                        type: object
+                        properties:
+                          chargeTokenId:
+                            type: string
+                            example: "ef1b6ff1-db34-4c62-b854-3ed4ba3c4049"
+                      href:
+                        type: string
+                        format: uri
+                        example: "https://www.payments.service.gov.uk/secure"
+                      method:
+                        type: string
+                        example: "POST"
+                  events:
+                    type: object
+                    properties:
+                      href:
+                        type: string
+                        format: uri
+                        example: "https://publicapi.payments.service.gov.uk/v1/payments/hu20sqlact5260q2nanm0q8u93/events"
+                      method:
+                        type: string
+                        example: "GET"
+                  refunds:
+                    type: object
+                    properties:
+                      href:
+                        type: string
+                        format: uri
+                        example: "https://publicapi.payments.service.gov.uk/v1/payments/hu20sqlact5260q2nanm0q8u93/refunds"
+                      method:
+                        type: string
+                        example: "GET"
+                  cancel:
+                    type: object
+                    properties:
+                      href:
+                        type: string
+                        format: uri
+                        example: "https://publicapi.payments.service.gov.uk/v1/payments/hu20sqlact5260q2nanm0q8u93/cancel"
+                      method:
+                        type: string
+                        example: "POST"
+    FetchPaymentResponse:
+      content:
+        application/json:
+          description: |
+            Payment response for the GovPay API
+
+            Docs: [https://docs.payments.service.gov.uk/api_reference/single_payment_reference/#example-response-for-get-information-about-a-single-payment](https://docs.payments.service.gov.uk/api_reference/single_payment_reference/#example-response-for-get-information-about-a-single-payment)
+          schema:
+            type: object
+            properties:
+              amount:
+                type: integer
+                format: int32
+                example: 3750
+              state:
+                type: object
+                properties:
+                  status:
+                    type: string
+                    example: "success"
+                  finished:
+                    type: boolean
+                    example: true
+              payment_id:
+                type: string
+                example: "hu20sqlact5260q2nanm0q8u93"
+              _links:
+                type: object
+                properties:
+                  next_url:
+                    type: object
+                    properties:
+                      href:
+                        type: string
+                        format: uri
+                        example: "https://www.payments.service.gov.uk/secure/ef1b6ff1-db34-4c62-b854-3ed4ba3c4049"
+                      method:
+                        type: string
+                        example: "GET"
+paths:
+  /pay/{localAuthority}:
+    post:
+      summary: Initiate a new payment
+      description: |
+        Initiate a GovPay payment via proxy. This will return a GovPay URL which we can forward the user to in order for them to make a payment.
+
+        Docs: [https://docs.payments.service.gov.uk/api_reference/create_a_payment_reference/](https://docs.payments.service.gov.uk/api_reference/create_a_payment_reference/)
+      tags:
+        - pay
+      parameters:
+        - $ref: "#/components/parameters/localAuthority"
+      requestBody:
+        $ref: "#/components/schemas/CreatePaymentRequest"
+      responses:
+        "200":
+          $ref: "#/components/responses/CreatePaymentResponse"
+  /pay/{localAuthority}/{paymentId}:
+    get:
+      summary: Get payment status
+      description: |
+        Get the status of a payment via a proxied request to the GovPay API
+
+        Docs: [https://docs.payments.service.gov.uk/api_reference/single_payment_reference/#get-information-about-a-single-payment-api-reference](https://docs.payments.service.gov.uk/api_reference/single_payment_reference/#get-information-about-a-single-payment-api-reference)
+      tags:
+        - pay
+      parameters:
+        - $ref: "#/components/parameters/localAuthority"
+        - $ref: "#/components/parameters/paymentId"
+      responses:
+        "200":
+          $ref: "#/components/responses/FetchPaymentResponse"
+  /payment-request/{paymentRequest}/pay:
+    post:
+      summary: Create a request for an "invite to pay" payment
+      description: |
+        Create a payment request via a proxied request to the GovPay API
+
+        Docs: [https://docs.payments.service.gov.uk/api_reference/create_a_payment_reference/](https://docs.payments.service.gov.uk/api_reference/create_a_payment_reference/)
+      tags:
+        - pay
+      parameters:
+        - $ref: "#/components/parameters/localAuthority"
+        - $ref: "#/components/parameters/paymentRequest"
+      requestBody:
+        $ref: "#/components/schemas/CreatePaymentRequest"
+      responses:
+        "200":
+          $ref: "#/components/responses/CreatePaymentResponse"
+  /payment-request/{paymentRequest}/payment/{paymentId}:
+    get:
+      summary: Get status for an "invite to pay" payment
+      description: |
+        Get the status of a payment via a proxied request to the GovPay API
+
+        Docs: [https://docs.payments.service.gov.uk/api_reference/single_payment_reference/#get-information-about-a-single-payment-api-reference](https://docs.payments.service.gov.uk/api_reference/single_payment_reference/#get-information-about-a-single-payment-api-reference)
+      tags:
+        - pay
+      parameters:
+        - $ref: "#/components/parameters/paymentRequest"
+        - $ref: "#/components/parameters/paymentId"
+      responses:
+        "200":
+          $ref: "#/components/responses/FetchPaymentResponse"
+  /invite-to-pay/{sessionId}:
+    post:
+      summary: Generate a payment request
+      tags:
+        - pay
+      parameters:
+        - $ref: "#/components/parameters/sessionId"
+      requestBody:
+        $ref: "#/components/schemas/InviteToPayRequest"
+      responses:
+        "200":
+          $ref: "#/components/responses/CreatePaymentResponse"
diff --git a/api.planx.uk/pay/index.test.ts b/api.planx.uk/modules/pay/index.test.ts
similarity index 97%
rename from api.planx.uk/pay/index.test.ts
rename to api.planx.uk/modules/pay/index.test.ts
index 4c24e51eef..ab4a129d37 100644
--- a/api.planx.uk/pay/index.test.ts
+++ b/api.planx.uk/modules/pay/index.test.ts
@@ -1,8 +1,8 @@
 import nock from "nock";
-import { queryMock } from "../tests/graphqlQueryMock";
+import { queryMock } from "../../tests/graphqlQueryMock";
 import supertest from "supertest";
 
-import app from "../server";
+import app from "../../server";
 
 jest.mock("@opensystemslab/planx-core", () => {
   return {
diff --git a/api.planx.uk/inviteToPay/paymentRequest.ts b/api.planx.uk/modules/pay/middleware.ts
similarity index 50%
rename from api.planx.uk/inviteToPay/paymentRequest.ts
rename to api.planx.uk/modules/pay/middleware.ts
index bc09f7ff34..f0a205899a 100644
--- a/api.planx.uk/inviteToPay/paymentRequest.ts
+++ b/api.planx.uk/modules/pay/middleware.ts
@@ -1,20 +1,25 @@
+import { NextFunction, Request, RequestHandler, Response } from "express";
 import { gql } from "graphql-request";
-import { NextFunction, Request, Response } from "express";
-import { ServerError } from "../errors";
-import {
-  postPaymentNotificationToSlack,
-  fetchPaymentViaProxyWithCallback,
-} from "../pay";
-import { GovUKPayment } from "@opensystemslab/planx-core/types";
-import { $api } from "../client";
+import { $api } from "../../client";
+import { ServerError } from "../../errors";
+
+/**
+ * Confirm that this local authority (aka team) has a pay token
+ * TODO: Check this against a DB value instead of env vars?
+ */
+export const isTeamUsingGovPay: RequestHandler = (req, _res, next) => {
+  const isSupported =
+    process.env[`GOV_UK_PAY_TOKEN_${req.params.localAuthority.toUpperCase()}`];
+
+  if (!isSupported) {
+    return next({
+      status: 400,
+      message: `GOV.UK Pay is not enabled for this local authority (${req.params.localAuthority})`,
+    });
+  }
 
-// https://docs.payments.service.gov.uk/api_reference/create_a_payment_reference/#json-body-parameters-for-39-create-a-payment-39
-interface GovPayCreatePayment {
-  amount: number;
-  reference: string;
-  description: string;
-  return_url: string;
-}
+  next();
+};
 
 interface GetPaymentRequestDetails {
   paymentRequest: {
@@ -31,9 +36,6 @@ interface GetPaymentRequestDetails {
   } | null;
 }
 
-// middleware used by routes:
-//  * /payment-request/:paymentRequest/pay
-//  * /payment-request/:paymentRequest/payment/:paymentId
 export async function fetchPaymentRequestDetails(
   req: Request,
   _res: Response,
@@ -82,7 +84,14 @@ export async function fetchPaymentRequestDetails(
   next();
 }
 
-// middleware used by /payment-request/:paymentRequest/pay?returnURL=...
+// https://docs.payments.service.gov.uk/api_reference/create_a_payment_reference/#json-body-parameters-for-39-create-a-payment-39
+interface GovPayCreatePayment {
+  amount: number;
+  reference: string;
+  description: string;
+  return_url: string;
+}
+
 export async function buildPaymentPayload(
   req: Request,
   _res: Response,
@@ -117,68 +126,3 @@ export async function buildPaymentPayload(
 
   next();
 }
-
-export const fetchPaymentRequestViaProxy = fetchPaymentViaProxyWithCallback(
-  async (req: Request, govUkResponse: GovUKPayment) => {
-    const paymentRequestId = req.params.paymentRequest;
-    if (paymentRequestId && govUkResponse?.state.status === "success") {
-      await markPaymentRequestAsPaid(paymentRequestId, govUkResponse);
-    }
-    await postPaymentNotificationToSlack(req, govUkResponse, "(invite to pay)");
-  },
-);
-
-interface MarkPaymentRequestAsPaid {
-  updatePaymentRequestPaidAt: {
-    affectedRows: number;
-  };
-  appendGovUKPaymentToSessionData: {
-    affectedRows: number;
-  };
-}
-
-export const markPaymentRequestAsPaid = async (
-  paymentRequestId: string,
-  govUkPayment: GovUKPayment,
-) => {
-  const query = gql`
-    mutation MarkPaymentRequestAsPaid(
-      $paymentRequestId: uuid!
-      $govUkPayment: jsonb
-    ) {
-      updatePaymentRequestPaidAt: update_payment_requests(
-        where: {
-          _and: { id: { _eq: $paymentRequestId }, paid_at: { _is_null: true } }
-        }
-        _set: { paid_at: "now()" }
-      ) {
-        affectedRows: affected_rows
-      }
-
-      # This will also overwrite any abandoned payments attempted on the session
-      appendGovUKPaymentToSessionData: update_lowcal_sessions(
-        _append: { data: $govUkPayment }
-        where: { payment_requests: { id: { _eq: $paymentRequestId } } }
-      ) {
-        affectedRows: affected_rows
-      }
-    }
-  `;
-  try {
-    const { updatePaymentRequestPaidAt, appendGovUKPaymentToSessionData } =
-      await $api.client.request<MarkPaymentRequestAsPaid>(query, {
-        paymentRequestId,
-        govUkPayment: { govUkPayment },
-      });
-    if (!updatePaymentRequestPaidAt?.affectedRows) {
-      throw Error(`payment request ${paymentRequestId} not updated`);
-    }
-    if (!appendGovUKPaymentToSessionData?.affectedRows) {
-      throw Error(
-        `session for payment request ${paymentRequestId} not updated`,
-      );
-    }
-  } catch (error) {
-    throw Error("Error marking payment request as paid: " + error);
-  }
-};
diff --git a/api.planx.uk/pay/proxy.ts b/api.planx.uk/modules/pay/proxy.ts
similarity index 91%
rename from api.planx.uk/pay/proxy.ts
rename to api.planx.uk/modules/pay/proxy.ts
index e946101872..66d9ee47a5 100644
--- a/api.planx.uk/pay/proxy.ts
+++ b/api.planx.uk/modules/pay/proxy.ts
@@ -1,6 +1,6 @@
 import { Request } from "express";
 import { fixRequestBody, Options } from "http-proxy-middleware";
-import { useProxy } from "../shared/middleware/proxy";
+import { useProxy } from "../../shared/middleware/proxy";
 
 export const usePayProxy = (options: Partial<Options>, req: Request) => {
   return useProxy({
diff --git a/api.planx.uk/modules/pay/routes.ts b/api.planx.uk/modules/pay/routes.ts
new file mode 100644
index 0000000000..928f3b764e
--- /dev/null
+++ b/api.planx.uk/modules/pay/routes.ts
@@ -0,0 +1,60 @@
+import { Router } from "express";
+import {
+  fetchPaymentViaProxy,
+  inviteToPay,
+  makeInviteToPayPaymentViaProxy,
+  makePaymentViaProxy,
+} from "./controller";
+import {
+  buildPaymentPayload,
+  fetchPaymentRequestDetails,
+  isTeamUsingGovPay,
+} from "./middleware";
+import {
+  inviteToPaySchema,
+  paymentProxySchema,
+  paymentRequestProxySchema,
+} from "./types";
+import { validate } from "../../shared/middleware/validate";
+import { fetchPaymentRequestViaProxy } from "./service/inviteToPay";
+
+const router = Router();
+
+router.post(
+  "/pay/:localAuthority",
+  isTeamUsingGovPay,
+  validate(paymentProxySchema),
+  makePaymentViaProxy,
+);
+
+router.get(
+  "/pay/:localAuthority/:paymentId",
+  isTeamUsingGovPay,
+  validate(paymentProxySchema),
+  fetchPaymentViaProxy,
+);
+
+router.post(
+  "/payment-request/:paymentRequest/pay",
+  fetchPaymentRequestDetails,
+  buildPaymentPayload,
+  isTeamUsingGovPay,
+  validate(paymentRequestProxySchema),
+  makeInviteToPayPaymentViaProxy,
+);
+
+router.get(
+  "/payment-request/:paymentRequest/payment/:paymentId",
+  fetchPaymentRequestDetails,
+  isTeamUsingGovPay,
+  validate(paymentProxySchema),
+  fetchPaymentRequestViaProxy,
+);
+
+router.post(
+  "/invite-to-pay/:sessionId",
+  validate(inviteToPaySchema),
+  inviteToPay,
+);
+
+export default router;
diff --git a/api.planx.uk/inviteToPay/createPaymentSendEvents.test.ts b/api.planx.uk/modules/pay/service/inviteToPay/createPaymentSendEvents.test.ts
similarity index 92%
rename from api.planx.uk/inviteToPay/createPaymentSendEvents.test.ts
rename to api.planx.uk/modules/pay/service/inviteToPay/createPaymentSendEvents.test.ts
index 4855cb0b36..09fc3cf2fc 100644
--- a/api.planx.uk/inviteToPay/createPaymentSendEvents.test.ts
+++ b/api.planx.uk/modules/pay/service/inviteToPay/createPaymentSendEvents.test.ts
@@ -1,10 +1,10 @@
 import supertest from "supertest";
-import app from "../server";
-import { createScheduledEvent } from "../lib/hasura/metadata";
-import { queryMock } from "../tests/graphqlQueryMock";
-import { flowWithInviteToPay } from "../tests/mocks/inviteToPayData";
+import app from "../../../../server";
+import { createScheduledEvent } from "../../../../lib/hasura/metadata";
+import { queryMock } from "../../../../tests/graphqlQueryMock";
+import { flowWithInviteToPay } from "../../../../tests/mocks/inviteToPayData";
 
-jest.mock("../lib/hasura/metadata");
+jest.mock("../../../../lib/hasura/metadata");
 const mockedCreateScheduledEvent = createScheduledEvent as jest.MockedFunction<
   typeof createScheduledEvent
 >;
diff --git a/api.planx.uk/inviteToPay/createPaymentSendEvents.ts b/api.planx.uk/modules/pay/service/inviteToPay/createPaymentSendEvents.ts
similarity index 95%
rename from api.planx.uk/inviteToPay/createPaymentSendEvents.ts
rename to api.planx.uk/modules/pay/service/inviteToPay/createPaymentSendEvents.ts
index 35ac8e3787..618fa1de43 100644
--- a/api.planx.uk/inviteToPay/createPaymentSendEvents.ts
+++ b/api.planx.uk/modules/pay/service/inviteToPay/createPaymentSendEvents.ts
@@ -1,13 +1,13 @@
 import { ComponentType } from "@opensystemslab/planx-core/types";
 import { NextFunction, Request, Response } from "express";
 import { gql } from "graphql-request";
-import { $api, $public } from "../client";
+import { $api, $public } from "../../../../client";
 import {
   ScheduledEventResponse,
   createScheduledEvent,
-} from "../lib/hasura/metadata";
-import { getMostRecentPublishedFlow } from "../helpers";
-import { Flow, Node, Team } from "../types";
+} from "../../../../lib/hasura/metadata";
+import { getMostRecentPublishedFlow } from "../../../../helpers";
+import { Flow, Node, Team } from "../../../../types";
 
 enum Destination {
   BOPS = "bops",
diff --git a/api.planx.uk/inviteToPay/inviteToPay.test.ts b/api.planx.uk/modules/pay/service/inviteToPay/index.test.ts
similarity index 85%
rename from api.planx.uk/inviteToPay/inviteToPay.test.ts
rename to api.planx.uk/modules/pay/service/inviteToPay/index.test.ts
index e7d245d867..1dac53c222 100644
--- a/api.planx.uk/inviteToPay/inviteToPay.test.ts
+++ b/api.planx.uk/modules/pay/service/inviteToPay/index.test.ts
@@ -1,6 +1,6 @@
 import supertest from "supertest";
-import { queryMock } from "../tests/graphqlQueryMock";
-import app from "../server";
+import { queryMock } from "../../../../tests/graphqlQueryMock";
+import app from "../../../../server";
 import {
   validSessionQueryMock,
   notFoundQueryMock,
@@ -10,14 +10,14 @@ import {
   unlockSessionQueryMock,
   getPublishedFlowDataQueryMock,
   createPaymentRequestQueryMock,
-} from "../tests/mocks/inviteToPayMocks";
+} from "../../../../tests/mocks/inviteToPayMocks";
 import {
   payee,
   applicant,
   validSession,
   notFoundSession,
   paymentRequestResponse,
-} from "../tests/mocks/inviteToPayData";
+} from "../../../../tests/mocks/inviteToPayData";
 
 describe("Invite to pay API route", () => {
   const inviteToPayBaseRoute = "/invite-to-pay";
@@ -69,10 +69,8 @@ describe("Invite to pay API route", () => {
         .send(invalidPostBody)
         .expect(400)
         .then((response) => {
-          expect(response.body).toHaveProperty(
-            "error",
-            "JSON body must contain payeeName",
-          );
+          expect(response.body).toHaveProperty("issues");
+          expect(response.body).toHaveProperty("name", "ZodError");
         });
     });
 
@@ -83,10 +81,8 @@ describe("Invite to pay API route", () => {
         .send(invalidPostBody)
         .expect(400)
         .then((response) => {
-          expect(response.body).toHaveProperty(
-            "error",
-            "JSON body must contain payeeEmail",
-          );
+          expect(response.body).toHaveProperty("issues");
+          expect(response.body).toHaveProperty("name", "ZodError");
         });
     });
 
diff --git a/api.planx.uk/inviteToPay/index.ts b/api.planx.uk/modules/pay/service/inviteToPay/index.ts
similarity index 78%
rename from api.planx.uk/inviteToPay/index.ts
rename to api.planx.uk/modules/pay/service/inviteToPay/index.ts
index b0d1494bd3..f7b095ca4d 100644
--- a/api.planx.uk/inviteToPay/index.ts
+++ b/api.planx.uk/modules/pay/service/inviteToPay/index.ts
@@ -1,4 +1,3 @@
-export * from "./inviteToPay";
 export * from "./paymentRequest";
 export * from "./sendPaymentEmail";
 export * from "./sendConfirmationEmail";
diff --git a/api.planx.uk/modules/pay/service/inviteToPay/paymentRequest.ts b/api.planx.uk/modules/pay/service/inviteToPay/paymentRequest.ts
new file mode 100644
index 0000000000..e69278d87e
--- /dev/null
+++ b/api.planx.uk/modules/pay/service/inviteToPay/paymentRequest.ts
@@ -0,0 +1,71 @@
+import { gql } from "graphql-request";
+import { Request } from "express";
+import { fetchPaymentViaProxyWithCallback } from "../../controller";
+import { GovUKPayment } from "@opensystemslab/planx-core/types";
+import { $api } from "../../../../client";
+import { postPaymentNotificationToSlack } from "../utils";
+
+export const fetchPaymentRequestViaProxy = fetchPaymentViaProxyWithCallback(
+  async (req: Request, govUkResponse: GovUKPayment) => {
+    const paymentRequestId = req.params.paymentRequest;
+    if (paymentRequestId && govUkResponse?.state.status === "success") {
+      await markPaymentRequestAsPaid(paymentRequestId, govUkResponse);
+    }
+    await postPaymentNotificationToSlack(req, govUkResponse, "(invite to pay)");
+  },
+);
+
+interface MarkPaymentRequestAsPaid {
+  updatePaymentRequestPaidAt: {
+    affectedRows: number;
+  };
+  appendGovUKPaymentToSessionData: {
+    affectedRows: number;
+  };
+}
+
+export const markPaymentRequestAsPaid = async (
+  paymentRequestId: string,
+  govUkPayment: GovUKPayment,
+) => {
+  const query = gql`
+    mutation MarkPaymentRequestAsPaid(
+      $paymentRequestId: uuid!
+      $govUkPayment: jsonb
+    ) {
+      updatePaymentRequestPaidAt: update_payment_requests(
+        where: {
+          _and: { id: { _eq: $paymentRequestId }, paid_at: { _is_null: true } }
+        }
+        _set: { paid_at: "now()" }
+      ) {
+        affectedRows: affected_rows
+      }
+
+      # This will also overwrite any abandoned payments attempted on the session
+      appendGovUKPaymentToSessionData: update_lowcal_sessions(
+        _append: { data: $govUkPayment }
+        where: { payment_requests: { id: { _eq: $paymentRequestId } } }
+      ) {
+        affectedRows: affected_rows
+      }
+    }
+  `;
+  try {
+    const { updatePaymentRequestPaidAt, appendGovUKPaymentToSessionData } =
+      await $api.client.request<MarkPaymentRequestAsPaid>(query, {
+        paymentRequestId,
+        govUkPayment: { govUkPayment },
+      });
+    if (!updatePaymentRequestPaidAt?.affectedRows) {
+      throw Error(`payment request ${paymentRequestId} not updated`);
+    }
+    if (!appendGovUKPaymentToSessionData?.affectedRows) {
+      throw Error(
+        `session for payment request ${paymentRequestId} not updated`,
+      );
+    }
+  } catch (error) {
+    throw Error("Error marking payment request as paid: " + error);
+  }
+};
diff --git a/api.planx.uk/inviteToPay/sendConfirmationEmail.test.ts b/api.planx.uk/modules/pay/service/inviteToPay/sendConfirmationEmail.test.ts
similarity index 94%
rename from api.planx.uk/inviteToPay/sendConfirmationEmail.test.ts
rename to api.planx.uk/modules/pay/service/inviteToPay/sendConfirmationEmail.test.ts
index 9e4126062b..b564744cfb 100644
--- a/api.planx.uk/inviteToPay/sendConfirmationEmail.test.ts
+++ b/api.planx.uk/modules/pay/service/inviteToPay/sendConfirmationEmail.test.ts
@@ -1,10 +1,10 @@
 import supertest from "supertest";
-import app from "../server";
-import { queryMock } from "../tests/graphqlQueryMock";
+import app from "../../../../server";
+import { queryMock } from "../../../../tests/graphqlQueryMock";
 import { sendAgentAndPayeeConfirmationEmail } from "./sendConfirmationEmail";
-import { sendEmail } from "../lib/notify";
+import { sendEmail } from "../../../../lib/notify";
 
-jest.mock("../lib/notify", () => ({
+jest.mock("../../../../lib/notify", () => ({
   sendEmail: jest.fn(),
 }));
 
diff --git a/api.planx.uk/inviteToPay/sendConfirmationEmail.ts b/api.planx.uk/modules/pay/service/inviteToPay/sendConfirmationEmail.ts
similarity index 92%
rename from api.planx.uk/inviteToPay/sendConfirmationEmail.ts
rename to api.planx.uk/modules/pay/service/inviteToPay/sendConfirmationEmail.ts
index 368f766731..fb69bad444 100644
--- a/api.planx.uk/inviteToPay/sendConfirmationEmail.ts
+++ b/api.planx.uk/modules/pay/service/inviteToPay/sendConfirmationEmail.ts
@@ -1,8 +1,8 @@
-import { $public, $api } from "../client";
-import { sendEmail } from "../lib/notify";
+import { $public, $api } from "../../../../client";
+import { sendEmail } from "../../../../lib/notify";
 import { gql } from "graphql-request";
-import { convertSlugToName } from "../modules/saveAndReturn/service/utils";
-import type { AgentAndPayeeSubmissionNotifyConfig } from "../types";
+import { convertSlugToName } from "../../../saveAndReturn/service/utils";
+import type { AgentAndPayeeSubmissionNotifyConfig } from "../../../../types";
 
 export async function sendAgentAndPayeeConfirmationEmail(sessionId: string) {
   const { personalisation, applicantEmail, payeeEmail, projectTypes } =
diff --git a/api.planx.uk/inviteToPay/sendPaymentEmail.test.ts b/api.planx.uk/modules/pay/service/inviteToPay/sendPaymentEmail.test.ts
similarity index 96%
rename from api.planx.uk/inviteToPay/sendPaymentEmail.test.ts
rename to api.planx.uk/modules/pay/service/inviteToPay/sendPaymentEmail.test.ts
index 4c4012e9f4..cc2c593d67 100644
--- a/api.planx.uk/inviteToPay/sendPaymentEmail.test.ts
+++ b/api.planx.uk/modules/pay/service/inviteToPay/sendPaymentEmail.test.ts
@@ -1,11 +1,11 @@
 import supertest from "supertest";
-import app from "../server";
-import { queryMock } from "../tests/graphqlQueryMock";
+import app from "../../../../server";
+import { queryMock } from "../../../../tests/graphqlQueryMock";
 
 import {
   validatePaymentRequestNotFoundQueryMock,
   validatePaymentRequestQueryMock,
-} from "../tests/mocks/inviteToPayMocks";
+} from "../../../../tests/mocks/inviteToPayMocks";
 import { CoreDomainClient } from "@opensystemslab/planx-core";
 
 jest
diff --git a/api.planx.uk/inviteToPay/sendPaymentEmail.ts b/api.planx.uk/modules/pay/service/inviteToPay/sendPaymentEmail.ts
similarity index 93%
rename from api.planx.uk/inviteToPay/sendPaymentEmail.ts
rename to api.planx.uk/modules/pay/service/inviteToPay/sendPaymentEmail.ts
index cf2f33fd96..c23a806896 100644
--- a/api.planx.uk/inviteToPay/sendPaymentEmail.ts
+++ b/api.planx.uk/modules/pay/service/inviteToPay/sendPaymentEmail.ts
@@ -3,12 +3,16 @@ import {
   calculateExpiryDate,
   convertSlugToName,
   getServiceLink,
-} from "../modules/saveAndReturn/service/utils";
-import { Template, getClientForTemplate, sendEmail } from "../lib/notify";
-import { InviteToPayNotifyConfig } from "../types";
-import { Team } from "../types";
+} from "../../../saveAndReturn/service/utils";
+import {
+  Template,
+  getClientForTemplate,
+  sendEmail,
+} from "../../../../lib/notify";
+import { InviteToPayNotifyConfig } from "../../../../types";
+import { Team } from "../../../../types";
 import type { PaymentRequest } from "@opensystemslab/planx-core/types";
-import { $public } from "../client";
+import { $public } from "../../../../client";
 
 interface SessionDetails {
   email: string;
diff --git a/api.planx.uk/modules/pay/service/utils.ts b/api.planx.uk/modules/pay/service/utils.ts
new file mode 100644
index 0000000000..d5057fd48c
--- /dev/null
+++ b/api.planx.uk/modules/pay/service/utils.ts
@@ -0,0 +1,53 @@
+import { GovUKPayment } from "@opensystemslab/planx-core/types";
+import { $api } from "../../../client";
+import { gql } from "graphql-request";
+
+import SlackNotify from "slack-notify";
+import { Request } from "express";
+
+export const addGovPayPaymentIdToPaymentRequest = async (
+  paymentRequestId: string,
+  govUKPayment: GovUKPayment,
+): Promise<void> => {
+  const query = gql`
+    mutation AddGovPayPaymentIdToPaymentRequest(
+      $paymentRequestId: uuid!
+      $govPayPaymentId: String
+    ) {
+      update_payment_requests_by_pk(
+        pk_columns: { id: $paymentRequestId }
+        _set: { govpay_payment_id: $govPayPaymentId }
+      ) {
+        id
+      }
+    }
+  `;
+  try {
+    await $api.client.request(query, {
+      paymentRequestId,
+      govPayPaymentId: govUKPayment.payment_id,
+    });
+  } catch (error) {
+    throw Error(`payment request ${paymentRequestId} not updated`);
+  }
+};
+
+export async function postPaymentNotificationToSlack(
+  req: Request,
+  govUkResponse: GovUKPayment,
+  label = "",
+) {
+  // if it's a prod payment, notify #planx-notifications so we can monitor for subsequent submissions
+  if (govUkResponse?.payment_provider !== "sandbox") {
+    const slack = SlackNotify(process.env.SLACK_WEBHOOK_URL!);
+    const getStatus = (state: GovUKPayment["state"]) =>
+      state.status + (state.message ? ` (${state.message})` : "");
+    const payMessage = `:coin: New GOV Pay payment ${label} *${
+      govUkResponse.payment_id
+    }* with status *${getStatus(govUkResponse.state)}* [${
+      req.params.localAuthority
+    }]`;
+    await slack.send(payMessage);
+    console.log("Payment notification posted to Slack");
+  }
+}
diff --git a/api.planx.uk/modules/pay/types.ts b/api.planx.uk/modules/pay/types.ts
new file mode 100644
index 0000000000..4c16ea8c8b
--- /dev/null
+++ b/api.planx.uk/modules/pay/types.ts
@@ -0,0 +1,51 @@
+import { z } from "zod";
+import { ValidatedRequestHandler } from "../../shared/middleware/validate";
+import { PaymentRequest } from "@opensystemslab/planx-core/types";
+
+export const paymentProxySchema = z.object({
+  query: z.object({
+    flowId: z.string().uuid(),
+    sessionId: z.string().uuid(),
+  }),
+  params: z.object({
+    localAuthority: z.string(),
+  }),
+});
+
+export type PaymentProxyController = ValidatedRequestHandler<
+  typeof paymentProxySchema,
+  Buffer
+>;
+
+export const inviteToPaySchema = z.object({
+  body: z.object({
+    payeeEmail: z.string().email(),
+    payeeName: z.string(),
+    applicantName: z.string(),
+    sessionPreviewKeys: z.array(z.array(z.string())),
+  }),
+  params: z.object({
+    sessionId: z.string().uuid(),
+  }),
+});
+
+export type InviteToPayController = ValidatedRequestHandler<
+  typeof inviteToPaySchema,
+  PaymentRequest
+>;
+
+export const paymentRequestProxySchema = z.object({
+  query: z.object({
+    flowId: z.string().uuid(),
+    sessionId: z.string().uuid(),
+  }),
+  params: z.object({
+    paymentRequest: z.string(),
+    localAuthority: z.string(),
+  }),
+});
+
+export type PaymentRequestProxyController = ValidatedRequestHandler<
+  typeof paymentRequestProxySchema,
+  Buffer
+>;
diff --git a/api.planx.uk/modules/sendEmail/controller.ts b/api.planx.uk/modules/sendEmail/controller.ts
index a91ae0bfdf..0f3570c02f 100644
--- a/api.planx.uk/modules/sendEmail/controller.ts
+++ b/api.planx.uk/modules/sendEmail/controller.ts
@@ -1,7 +1,7 @@
 import {
   sendSinglePaymentEmail,
   sendAgentAndPayeeConfirmationEmail,
-} from "../../inviteToPay";
+} from "../pay/service/inviteToPay";
 import { sendSingleApplicationEmail } from "../saveAndReturn/service/utils";
 import { ServerError } from "../../errors";
 import { NextFunction } from "express";
diff --git a/api.planx.uk/modules/webhooks/routes.ts b/api.planx.uk/modules/webhooks/routes.ts
index dc7c1bbbcd..233817d1c4 100644
--- a/api.planx.uk/modules/webhooks/routes.ts
+++ b/api.planx.uk/modules/webhooks/routes.ts
@@ -1,6 +1,6 @@
 import { Router } from "express";
 import { useHasuraAuth } from "../auth/middleware";
-import { createPaymentSendEvents } from "../../inviteToPay/createPaymentSendEvents";
+import { createPaymentSendEvents } from "../pay/service/inviteToPay/createPaymentSendEvents";
 import { validate } from "../../shared/middleware/validate";
 import {
   createPaymentExpiryEventsController,
diff --git a/api.planx.uk/pay/utils.ts b/api.planx.uk/pay/utils.ts
deleted file mode 100644
index f731abf085..0000000000
--- a/api.planx.uk/pay/utils.ts
+++ /dev/null
@@ -1,30 +0,0 @@
-import { GovUKPayment } from "@opensystemslab/planx-core/types";
-import { $api } from "../client";
-import { gql } from "graphql-request";
-
-export const addGovPayPaymentIdToPaymentRequest = async (
-  paymentRequestId: string,
-  govUKPayment: GovUKPayment,
-): Promise<void> => {
-  const query = gql`
-    mutation AddGovPayPaymentIdToPaymentRequest(
-      $paymentRequestId: uuid!
-      $govPayPaymentId: String
-    ) {
-      update_payment_requests_by_pk(
-        pk_columns: { id: $paymentRequestId }
-        _set: { govpay_payment_id: $govPayPaymentId }
-      ) {
-        id
-      }
-    }
-  `;
-  try {
-    await $api.client.request(query, {
-      paymentRequestId,
-      govPayPaymentId: govUKPayment.payment_id,
-    });
-  } catch (error) {
-    throw Error(`payment request ${paymentRequestId} not updated`);
-  }
-};
diff --git a/api.planx.uk/server.ts b/api.planx.uk/server.ts
index 75a50208f5..3f7b65f7a5 100644
--- a/api.planx.uk/server.ts
+++ b/api.planx.uk/server.ts
@@ -4,7 +4,6 @@ import assert from "assert";
 import cookieParser from "cookie-parser";
 import cookieSession from "cookie-session";
 import cors from "cors";
-import { stringify } from "csv-stringify";
 import express, { ErrorRequestHandler } from "express";
 import noir from "pino-noir";
 import pinoLogger from "express-pino-logger";
@@ -13,17 +12,6 @@ import passport from "passport";
 import helmet from "helmet";
 
 import { ServerError } from "./errors";
-import {
-  makePaymentViaProxy,
-  fetchPaymentViaProxy,
-  makeInviteToPayPaymentViaProxy,
-} from "./pay";
-import {
-  inviteToPay,
-  fetchPaymentRequestDetails,
-  buildPaymentPayload,
-  fetchPaymentRequestViaProxy,
-} from "./inviteToPay";
 import { useHasuraAuth } from "./modules/auth/middleware";
 
 import airbrake from "./airbrake";
@@ -46,6 +34,7 @@ import saveAndReturnRoutes from "./modules/saveAndReturn/routes";
 import sendEmailRoutes from "./modules/sendEmail/routes";
 import fileRoutes from "./modules/file/routes";
 import gisRoutes from "./modules/gis/routes";
+import payRoutes from "./modules/pay/routes";
 import { useSwaggerDocs } from "./docs";
 import { Role } from "@opensystemslab/planx-core/types";
 
@@ -116,25 +105,6 @@ app.get("/download-application-files/:sessionId", downloadApplicationFiles);
   assert(process.env[`GOV_UK_PAY_TOKEN_${authority}`]);
 });
 
-// used by startNewPayment() in @planx/components/Pay/Public/Pay.tsx
-app.post("/pay/:localAuthority", makePaymentViaProxy);
-
-// used by refetchPayment() in @planx/components/Pay/Public/Pay.tsx
-app.get("/pay/:localAuthority/:paymentId", fetchPaymentViaProxy);
-
-app.post(
-  "/payment-request/:paymentRequest/pay",
-  fetchPaymentRequestDetails,
-  buildPaymentPayload,
-  makeInviteToPayPaymentViaProxy,
-);
-
-app.get(
-  "/payment-request/:paymentRequest/payment/:paymentId",
-  fetchPaymentRequestDetails,
-  fetchPaymentRequestViaProxy,
-);
-
 // needed for storing original URL to redirect to in login flow
 app.use(
   cookieSession({
@@ -170,28 +140,7 @@ app.use(saveAndReturnRoutes);
 app.use(sendEmailRoutes);
 app.use("/flows", flowRoutes);
 app.use(gisRoutes);
-
-// allows an applicant to download their application data on the Confirmation page
-app.post("/download-application", async (req, res, next) => {
-  if (!req.body) {
-    res.send({
-      message: "Missing application `data` to download",
-    });
-  }
-
-  try {
-    // build a CSV and stream the response
-    stringify(req.body, {
-      columns: ["question", "responses", "metadata"],
-      header: true,
-    }).pipe(res);
-    res.header("Content-type", "text/csv");
-  } catch (err) {
-    next(err);
-  }
-});
-
-app.post("/invite-to-pay/:sessionId", inviteToPay);
+app.use(payRoutes);
 
 const errorHandler: ErrorRequestHandler = (errorObject, _req, res, _next) => {
   const { status = 500, message = "Something went wrong" } = (() => {