diff --git a/.env.example b/.env.example
index e226500261..fbdd5ecd11 100644
--- a/.env.example
+++ b/.env.example
@@ -22,7 +22,6 @@ MICROSOFT_CLIENT_SECRET=👻
 
 # AWS credentials for uploading user files from local and pull request environments to a staging S3 bucket
 AWS_S3_REGION=eu-west-2
-AWS_S3_ACL=public-read
 AWS_S3_BUCKET=👻
 AWS_ACCESS_KEY=👻
 AWS_SECRET_KEY=👻
diff --git a/api.planx.uk/modules/file/service/deleteFile.ts b/api.planx.uk/modules/file/service/deleteFile.ts
index 8ea143fbca..87557b31ea 100644
--- a/api.planx.uk/modules/file/service/deleteFile.ts
+++ b/api.planx.uk/modules/file/service/deleteFile.ts
@@ -1,26 +1,26 @@
 import type { DeleteObjectsCommandInput } from "@aws-sdk/client-s3";
-import type { DeleteObjectsRequest } from "aws-sdk/clients/s3.js";
 import { getS3KeyFromURL, s3Factory } from "./utils.js";
 
 export const deleteFilesByURL = async (
   fileURLs: string[],
 ): Promise<string[]> => {
   const keys = fileURLs.map(getS3KeyFromURL);
-  return await deleteFilesByKey(keys);
+  const result = await deleteFilesByKey(keys);
+  return result;
 };
 
 export const deleteFilesByKey = async (keys: string[]): Promise<string[]> => {
   const s3 = s3Factory();
-  const params = getDeleteFilesParams(keys) as DeleteObjectsCommandInput;
+  const params = getDeleteFilesParams(keys);
   try {
-    s3.deleteObjects(params);
+    await s3.deleteObjects(params);
     return keys;
   } catch (error) {
     throw Error(`Failed to delete S3 files: ${error}`);
   }
 };
 
-const getDeleteFilesParams = (keys: string[]): DeleteObjectsRequest => ({
+const getDeleteFilesParams = (keys: string[]): DeleteObjectsCommandInput => ({
   Bucket: process.env.AWS_S3_BUCKET!,
   Delete: {
     Objects: keys.map((key) => ({ Key: key })),
diff --git a/api.planx.uk/modules/file/service/getFile.ts b/api.planx.uk/modules/file/service/getFile.ts
index dae32f703f..db40874ba1 100644
--- a/api.planx.uk/modules/file/service/getFile.ts
+++ b/api.planx.uk/modules/file/service/getFile.ts
@@ -4,14 +4,20 @@ import { s3Factory } from "./utils.js";
 export const getFileFromS3 = async (fileId: string) => {
   const s3 = s3Factory();
 
-  const params = {
+  const params: PutObjectCommandInput = {
     Key: fileId,
-  } as PutObjectCommandInput;
+    Bucket: process.env.AWS_S3_BUCKET,
+  };
 
   const file = await s3.getObject(params);
 
+  // TODO: test this
+  if (!file.Body) throw Error(`Missing body from S3 file ${fileId}`);
+
+  const body = Buffer.from(await file.Body.transformToByteArray());
+
   return {
-    body: file.Body,
+    body,
     isPrivate: file.Metadata?.is_private === "true",
     headers: {
       "Content-Type": file.ContentType,
diff --git a/api.planx.uk/modules/file/service/uploadFile.ts b/api.planx.uk/modules/file/service/uploadFile.ts
index caa8a004be..5d4974b0a0 100644
--- a/api.planx.uk/modules/file/service/uploadFile.ts
+++ b/api.planx.uk/modules/file/service/uploadFile.ts
@@ -19,7 +19,7 @@ export const uploadPublicFile = async (
   const { params, key, fileType } = generateFileParams(file, filename, filekey);
 
   await s3.putObject(params);
-  const fileUrl = buildFileUrl(key, "public");
+  const fileUrl = await buildFileUrl(key, "public");
 
   return {
     fileType,
@@ -41,7 +41,7 @@ export const uploadPrivateFile = async (
   };
 
   await s3.putObject(params);
-  const fileUrl = buildFileUrl(key, "private");
+  const fileUrl = await buildFileUrl(key, "private");
 
   return {
     fileType,
@@ -75,13 +75,14 @@ export function generateFileParams(
   const fileType = mime.getType(filename);
   const key = `${filekey || nanoid()}/${filename}`;
 
-  const params = {
-    ACL: process.env.AWS_S3_ACL,
+  const params: PutObjectCommandInput = {
+    ACL: "public-read",
+    Bucket: process.env.AWS_S3_BUCKET,
     Key: key,
     Body: file?.buffer || JSON.stringify(file),
     ContentDisposition: `inline;filename="${filename}"`,
     ContentType: file?.mimetype || "application/json",
-  } as PutObjectCommandInput;
+  };
 
   return {
     fileType,
diff --git a/api.planx.uk/modules/file/service/utils.ts b/api.planx.uk/modules/file/service/utils.ts
index c1846eee95..0f95e170e5 100644
--- a/api.planx.uk/modules/file/service/utils.ts
+++ b/api.planx.uk/modules/file/service/utils.ts
@@ -3,15 +3,11 @@ import { isLiveEnv } from "../../../helpers.js";
 
 export function s3Factory() {
   return new S3({
-    // The key params is no longer supported in v3, and can be removed.
-    // @deprecated The object needs to be passed to individual operations where it's intended.
-    params: { Bucket: process.env.AWS_S3_BUCKET },
-
-    region: process.env.AWS_S3_REGION,
+    region: process.env.AWS_S3_REGION!,
 
     credentials: {
-      accessKeyId: process.env.AWS_ACCESS_KEY,
-      secretAccessKey: process.env.AWS_SECRET_KEY,
+      accessKeyId: process.env.AWS_ACCESS_KEY!,
+      secretAccessKey: process.env.AWS_SECRET_KEY!,
     },
 
     ...useMinio(),
diff --git a/api.planx.uk/modules/send/utils/exportZip.ts b/api.planx.uk/modules/send/utils/exportZip.ts
index e67a32ce7c..da068d0aef 100644
--- a/api.planx.uk/modules/send/utils/exportZip.ts
+++ b/api.planx.uk/modules/send/utils/exportZip.ts
@@ -245,7 +245,7 @@ export class ExportZip {
     const { body } = await getFileFromS3(decodedS3Key);
     if (!body) throw new Error("file not found");
 
-    this.zip.addFile(name, body as Buffer);
+    this.zip.addFile(name, body);
   }
 
   toBuffer(): Buffer {
diff --git a/docker-compose.yml b/docker-compose.yml
index 8569cc75dd..7243ae7c86 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -117,7 +117,6 @@ services:
       API_URL_EXT: ${API_URL_EXT}
       APP_ENVIRONMENT: ${APP_ENVIRONMENT}
       AWS_ACCESS_KEY: ${AWS_ACCESS_KEY}
-      AWS_S3_ACL: ${AWS_S3_ACL}
       AWS_S3_BUCKET: ${AWS_S3_BUCKET}
       AWS_S3_REGION: ${AWS_S3_REGION}
       AWS_SECRET_KEY: ${AWS_SECRET_KEY}
diff --git a/infrastructure/application/index.ts b/infrastructure/application/index.ts
index 5e599d415d..764e3913ca 100644
--- a/infrastructure/application/index.ts
+++ b/infrastructure/application/index.ts
@@ -339,7 +339,6 @@ export = async () => {
             name: "AWS_S3_BUCKET",
             value: pulumi.interpolate`${apiBucket.bucket}`,
           },
-          { name: "AWS_S3_ACL", value: "public-read" },
           {
             name: "FILE_API_KEY",
             value: config.requireSecret("file-api-key"),