diff --git a/schemas/discriminated.json b/schemas/discriminated.json
index 29649659..32f6d0ff 100644
--- a/schemas/discriminated.json
+++ b/schemas/discriminated.json
@@ -13,6 +13,155 @@
     }
   ],
   "definitions": {
+    "Application<\"pa\">": {
+      "additionalProperties": false,
+      "properties": {
+        "applicationType": {
+          "$ref": "#/definitions/ApplicationTypeKeys",
+          "description": "Enforces an application type which matches the given primary type"
+        }
+      },
+      "required": [
+        "applicationType"
+      ],
+      "type": "object"
+    },
+    "Application<\"pp\">": {
+      "additionalProperties": false,
+      "properties": {
+        "applicationType": {
+          "$ref": "#/definitions/ApplicationTypeKeys",
+          "description": "Enforces an application type which matches the given primary type"
+        }
+      },
+      "required": [
+        "applicationType"
+      ],
+      "type": "object"
+    },
+    "Application<\"wtt\">": {
+      "additionalProperties": false,
+      "properties": {
+        "applicationType": {
+          "$ref": "#/definitions/ApplicationTypeKeys",
+          "description": "Enforces an application type which matches the given primary type"
+        }
+      },
+      "required": [
+        "applicationType"
+      ],
+      "type": "object"
+    },
+    "ApplicationTypeKeys": {
+      "enum": [
+        "advertConsent",
+        "amendment",
+        "amendment.minorMaterial",
+        "amendment.nonMaterial",
+        "approval",
+        "approval.conditions",
+        "approval.reservedMatters",
+        "complianceConfirmation",
+        "environmentalImpact",
+        "environmentalImpact.scoping",
+        "environmentalImpact.screening",
+        "hazardousSubstanceConsent",
+        "hedgerowRemovalNotice",
+        "landDrainageConsent",
+        "ldc",
+        "ldc.breachOfCondition",
+        "ldc.existing",
+        "ldc.listedBuildingWorks",
+        "ldc.proposed",
+        "listed",
+        "notifyCompletion",
+        "obligation",
+        "obligation.discharge",
+        "obligation.modify",
+        "onshoreExtractionOilAndGas",
+        "onshoreExtractionOilAndGas.other",
+        "onshoreExtractionOilAndGas.pp.extension",
+        "onshoreExtractionOilAndGas.pp.waste",
+        "onshoreExtractionOilAndGas.pp.working",
+        "onshoreExtractionOilAndGas.review",
+        "onshoreExtractionOilAndGas.variation",
+        "pa",
+        "pa.part1.classA",
+        "pa.part1.classAA",
+        "pa.part3.classG",
+        "pa.part3.classM",
+        "pa.part3.classMA",
+        "pa.part3.classN",
+        "pa.part3.classQ",
+        "pa.part3.classR",
+        "pa.part3.classS",
+        "pa.part3.classT",
+        "pa.part3.classV",
+        "pa.part4.classBB",
+        "pa.part4.classBC",
+        "pa.part4.classCA",
+        "pa.part4.classE",
+        "pa.part6",
+        "pa.part6.classA",
+        "pa.part6.classB",
+        "pa.part6.classE",
+        "pa.part7.classC",
+        "pa.part7.classM",
+        "pa.part9.classD",
+        "pa.part11.classB",
+        "pa.part14.classA",
+        "pa.part14.classB",
+        "pa.part14.classJ",
+        "pa.part14.classK",
+        "pa.part14.classOA",
+        "pa.part16.classA",
+        "pa.part17",
+        "pa.part17.classB",
+        "pa.part17.classC",
+        "pa.part17.classG",
+        "pa.part18.classA",
+        "pa.part19.classTA",
+        "pa.part20.classA",
+        "pa.part20.classAA",
+        "pa.part20.classAB",
+        "pa.part20.classAC",
+        "pa.part20.classAD",
+        "pa.part20.classZA",
+        "pp",
+        "pp.full",
+        "pp.full.advertConsent",
+        "pp.full.demolition",
+        "pp.full.fastTrack.affordable",
+        "pp.full.householder",
+        "pp.full.householder.listed",
+        "pp.full.householder.retro",
+        "pp.full.major",
+        "pp.full.major.technicalDetails",
+        "pp.full.major.technicalDetails.waste",
+        "pp.full.major.waste",
+        "pp.full.minor",
+        "pp.full.minor.listed",
+        "pp.full.minor.technicalDetails",
+        "pp.mineralExtraction",
+        "pp.outline",
+        "pp.outline.all",
+        "pp.outline.some",
+        "pp.outline.minor",
+        "pp.outline.minor.all",
+        "pp.outline.minor.some",
+        "pp.outline.major",
+        "pp.outline.major.all",
+        "pp.outline.major.all.waste",
+        "pp.outline.major.some",
+        "pp.outline.major.some.waste",
+        "pp.pip",
+        "rightsOfWayOrder",
+        "wtt",
+        "wtt.consent",
+        "wtt.notice"
+      ],
+      "type": "string"
+    },
     "PPUser": {
       "additionalProperties": false,
       "properties": {
@@ -41,12 +190,16 @@
         "data": {
           "additionalProperties": false,
           "properties": {
+            "application": {
+              "$ref": "#/definitions/Application%3C%22pp%22%3E"
+            },
             "user": {
               "$ref": "#/definitions/PPUser"
             }
           },
           "required": [
-            "user"
+            "user",
+            "application"
           ],
           "type": "object"
         },
@@ -68,12 +221,16 @@
         "data": {
           "additionalProperties": false,
           "properties": {
+            "application": {
+              "$ref": "#/definitions/Application%3C%22pa%22%3E"
+            },
             "user": {
               "$ref": "#/definitions/UserBase"
             }
           },
           "required": [
-            "user"
+            "user",
+            "application"
           ],
           "type": "object"
         },
@@ -133,12 +290,16 @@
         "data": {
           "additionalProperties": false,
           "properties": {
+            "application": {
+              "$ref": "#/definitions/Application%3C%22wtt%22%3E"
+            },
             "user": {
               "$ref": "#/definitions/WTTUser"
             }
           },
           "required": [
-            "user"
+            "user",
+            "application"
           ],
           "type": "object"
         },
diff --git a/types/schemas/digitalPlanningApplication/enums/ApplicationTypes.ts b/types/schemas/digitalPlanningApplication/enums/ApplicationTypes.ts
index 40bc0d7c..67a32d98 100644
--- a/types/schemas/digitalPlanningApplication/enums/ApplicationTypes.ts
+++ b/types/schemas/digitalPlanningApplication/enums/ApplicationTypes.ts
@@ -173,7 +173,7 @@ export const ApplicationTypes = {
     'Works to trees - Notification of proposed works to a tree in a Conservation Area',
 };
 
-type ApplicationTypeKeys = keyof typeof ApplicationTypes;
+export type ApplicationTypeKeys = keyof typeof ApplicationTypes;
 
 type GenericApplicationType<TKey extends ApplicationTypeKeys> = {
   value: TKey;
diff --git a/types/schemas/discriminated/Application.ts b/types/schemas/discriminated/Application.ts
new file mode 100644
index 00000000..bbc860b9
--- /dev/null
+++ b/types/schemas/discriminated/Application.ts
@@ -0,0 +1,17 @@
+import {
+  ApplicationTypeKeys,
+  PrimaryApplicationTypes,
+} from '../digitalPlanningApplication/enums/ApplicationTypes';
+
+/**
+ * @internal
+ * @description Enforces an application type which matches the given primary type
+ */
+type ApplicationTypeOf<T extends PrimaryApplicationTypes> = Extract<
+  ApplicationTypeKeys,
+  `${T}.${string}`
+>;
+
+export interface Application<T extends PrimaryApplicationTypes> {
+  applicationType: ApplicationTypeOf<T>;
+}
diff --git a/types/schemas/discriminated/index.ts b/types/schemas/discriminated/index.ts
index 580f77b9..1fe5c602 100644
--- a/types/schemas/discriminated/index.ts
+++ b/types/schemas/discriminated/index.ts
@@ -1,10 +1,12 @@
 import {PrimaryApplicationTypes} from '../digitalPlanningApplication/enums/ApplicationTypes';
+import {Application} from './Application';
 import {User} from './User';
 
 interface GenericApplication<T extends PrimaryApplicationTypes> {
   primaryApplicationType: T;
   data: {
     user: User<T>;
+    application: Application<T>;
   };
 }