diff --git a/api.planx.uk/modules/send/bops/bops.test.ts b/api.planx.uk/modules/send/bops/bops.test.ts
index 3342e08b19..76dfe8f22e 100644
--- a/api.planx.uk/modules/send/bops/bops.test.ts
+++ b/api.planx.uk/modules/send/bops/bops.test.ts
@@ -37,7 +37,7 @@ describe(`sending an application to BOPS (v2)`, () => {
         bopsApplications: [],
       },
       variables: {
-        session_id: "123",
+        session_id: "37e3649b-4854-4249-a5c3-7937c1b952b9",
         search_string: "%/api/v2/planning_applications",
       },
     });
@@ -93,7 +93,7 @@ describe(`sending an application to BOPS (v2)`, () => {
     await supertest(app)
       .post("/bops/southwark")
       .set({ Authorization: process.env.HASURA_PLANX_API_KEY! })
-      .send({ payload: { sessionId: "123" } })
+      .send({ payload: { sessionId: "37e3649b-4854-4249-a5c3-7937c1b952b9" } })
       .expect(200)
       .then((res) => {
         expect(res.body).toEqual({
@@ -108,7 +108,7 @@ describe(`sending an application to BOPS (v2)`, () => {
   it("requires auth", async () => {
     await supertest(app)
       .post("/bops/southwark")
-      .send({ payload: { sessionId: "123" } })
+      .send({ payload: { sessionId: "37e3649b-4854-4249-a5c3-7937c1b952b9" } })
       .expect(401);
   });
 
@@ -119,7 +119,8 @@ describe(`sending an application to BOPS (v2)`, () => {
       .send({ payload: null })
       .expect(400)
       .then((res) => {
-        expect(res.body.error).toMatch(/Missing application/);
+        expect(res.body).toHaveProperty("issues");
+        expect(res.body).toHaveProperty("name", "ZodError");
       });
   });
 
@@ -127,7 +128,7 @@ describe(`sending an application to BOPS (v2)`, () => {
     await supertest(app)
       .post("/bops/unsupported-team")
       .set({ Authorization: process.env.HASURA_PLANX_API_KEY! })
-      .send({ payload: { sessionId: "123" } })
+      .send({ payload: { sessionId: "37e3649b-4854-4249-a5c3-7937c1b952b9" } })
       .expect(500)
       .then((res) => {
         expect(res.body.error).toMatch(
@@ -137,6 +138,9 @@ describe(`sending an application to BOPS (v2)`, () => {
   });
 
   it("does not re-send an application which has already been submitted", async () => {
+    const previouslySubmittedApplicationID =
+      "07e4dd0d-ec3c-48f5-adc7-aee90116f6c7";
+
     queryMock.mockQuery({
       name: "FindApplication",
       data: {
@@ -145,7 +149,7 @@ describe(`sending an application to BOPS (v2)`, () => {
         ],
       },
       variables: {
-        session_id: "previously_submitted_app",
+        session_id: previouslySubmittedApplicationID,
         search_string: "%/api/v2/planning_applications",
       },
     });
@@ -153,11 +157,11 @@ describe(`sending an application to BOPS (v2)`, () => {
     await supertest(app)
       .post("/bops/southwark")
       .set({ Authorization: process.env.HASURA_PLANX_API_KEY! })
-      .send({ payload: { sessionId: "previously_submitted_app" } })
+      .send({ payload: { sessionId: previouslySubmittedApplicationID } })
       .expect(200)
       .then((res) => {
         expect(res.body).toEqual({
-          sessionId: "previously_submitted_app",
+          sessionId: previouslySubmittedApplicationID,
           bopsId: "bops_app_id",
           message: "Skipping send, already successfully submitted",
         });
diff --git a/api.planx.uk/modules/send/bops/bops.ts b/api.planx.uk/modules/send/bops/bops.ts
index 334d9f06df..e706711fb7 100644
--- a/api.planx.uk/modules/send/bops/bops.ts
+++ b/api.planx.uk/modules/send/bops/bops.ts
@@ -1,16 +1,10 @@
 import type { AxiosResponse } from "axios";
 import axios from "axios";
 import { markSessionAsSubmitted } from "../../saveAndReturn/service/utils.js";
-import type { NextFunction, Request, Response } from "express";
 import { gql } from "graphql-request";
 import { $api } from "../../../client/index.js";
 import { ServerError } from "../../../errors/index.js";
-
-interface SendToBOPSRequest {
-  payload: {
-    sessionId: string;
-  };
-}
+import type { SendIntegrationController } from "../types.js";
 
 interface CreateBopsApplication {
   insertBopsApplication: {
@@ -19,23 +13,16 @@ interface CreateBopsApplication {
   };
 }
 
-const sendToBOPS = async (req: Request, res: Response, next: NextFunction) => {
-  // `/bops/:localAuthority` is only called via Hasura's scheduled event webhook now, so body is wrapped in a "payload" key
-  const { payload }: SendToBOPSRequest = req.body;
-  if (!payload) {
-    return next(
-      new ServerError({
-        status: 400,
-        message: `Missing application payload data to send to BOPS`,
-      }),
-    );
-  }
+const sendToBOPS: SendIntegrationController = async (_req, res, next) => {
+  const {
+    payload: { sessionId },
+  } = res.locals.parsedReq.body;
 
   // confirm that this session has not already been successfully submitted before proceeding
-  const submittedApp = await checkBOPSAuditTable(payload?.sessionId, "v2");
+  const submittedApp = await checkBOPSAuditTable(sessionId, "v2");
   if (submittedApp?.message === "Application created") {
     return res.status(200).send({
-      sessionId: payload?.sessionId,
+      sessionId,
       bopsId: submittedApp?.id,
       message: `Skipping send, already successfully submitted`,
     });
@@ -44,7 +31,7 @@ const sendToBOPS = async (req: Request, res: Response, next: NextFunction) => {
   // confirm this local authority (aka team) is supported by BOPS before creating the proxy
   // a local or staging API instance should send to the BOPS staging endpoint
   // production should send to the BOPS production endpoint
-  const localAuthority = req.params.localAuthority;
+  const localAuthority = res.locals.parsedReq.params.localAuthority;
   const env =
     process.env.APP_ENVIRONMENT === "production" ? "production" : "staging";
 
@@ -54,9 +41,7 @@ const sendToBOPS = async (req: Request, res: Response, next: NextFunction) => {
       encryptionKey: process.env.ENCRYPTION_KEY!,
       env,
     });
-    const exportData = await $api.export.digitalPlanningDataPayload(
-      payload?.sessionId,
-    );
+    const exportData = await $api.export.digitalPlanningDataPayload(sessionId);
 
     const bopsResponse = await axios({
       method: "POST",
@@ -70,7 +55,7 @@ const sendToBOPS = async (req: Request, res: Response, next: NextFunction) => {
     })
       .then(async (res: AxiosResponse<{ id: string }>) => {
         // Mark session as submitted so that reminder and expiry emails are not triggered
-        markSessionAsSubmitted(payload?.sessionId);
+        markSessionAsSubmitted(sessionId);
 
         const applicationId = await $api.client.request<CreateBopsApplication>(
           gql`
@@ -105,7 +90,7 @@ const sendToBOPS = async (req: Request, res: Response, next: NextFunction) => {
             request: exportData,
             response: res.data,
             response_headers: res.headers,
-            session_id: payload?.sessionId,
+            session_id: sessionId,
           },
         );
 
@@ -119,14 +104,14 @@ const sendToBOPS = async (req: Request, res: Response, next: NextFunction) => {
       .catch((error) => {
         if (error.response) {
           throw new Error(
-            `Sending to BOPS v2 failed (${[localAuthority, payload?.sessionId]
+            `Sending to BOPS v2 failed (${[localAuthority, sessionId]
               .filter(Boolean)
               .join(" - ")}):\n${JSON.stringify(error.response.data, null, 2)}`,
           );
         } else {
           // re-throw other errors
           throw new Error(
-            `Sending to BOPS v2 failed (${[localAuthority, payload?.sessionId]
+            `Sending to BOPS v2 failed (${[localAuthority, sessionId]
               .filter(Boolean)
               .join(" - ")}):\n${error}`,
           );
@@ -137,10 +122,7 @@ const sendToBOPS = async (req: Request, res: Response, next: NextFunction) => {
     next(
       new ServerError({
         status: 500,
-        message: `Sending to BOPS v2 failed (${[
-          localAuthority,
-          payload?.sessionId,
-        ]
+        message: `Sending to BOPS v2 failed (${[localAuthority, sessionId]
           .filter(Boolean)
           .join(" - ")}):\n${err}`,
         cause: err,
diff --git a/api.planx.uk/modules/send/email/index.test.ts b/api.planx.uk/modules/send/email/index.test.ts
index d5b9fcad84..f5e17e5231 100644
--- a/api.planx.uk/modules/send/email/index.test.ts
+++ b/api.planx.uk/modules/send/email/index.test.ts
@@ -64,7 +64,7 @@ describe(`sending an application by email to a planning office`, () => {
       data: {
         session: { data: {} },
       },
-      variables: { id: "123" },
+      variables: { id: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49" },
       matchOnVariables: true,
     });
 
@@ -77,16 +77,16 @@ describe(`sending an application by email to a planning office`, () => {
           flow: { slug: "test-flow", name: "Test Flow" },
         },
       },
-      variables: { id: "123" },
+      variables: { id: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49" },
     });
 
     queryMock.mockQuery({
       name: "MarkSessionAsSubmitted",
       matchOnVariables: false,
       data: {
-        session: { id: "123" },
+        session: { id: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49" },
       },
-      variables: { sessionId: "123" },
+      variables: { sessionId: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49" },
     });
 
     queryMock.mockQuery({
@@ -96,7 +96,7 @@ describe(`sending an application by email to a planning office`, () => {
         application: { id: 1 },
       },
       variables: {
-        sessionId: "123",
+        sessionId: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49",
         teamSlug: "southwark",
         recipient: "planning.office.example@council.gov.uk",
         request: {
@@ -116,7 +116,7 @@ describe(`sending an application by email to a planning office`, () => {
     await supertest(app)
       .post("/email-submission/southwark")
       .set({ Authorization: process.env.HASURA_PLANX_API_KEY! })
-      .send({ payload: { sessionId: "123" } })
+      .send({ payload: { sessionId: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49" } })
       .expect(200)
       .then((res) => {
         expect(res.body).toEqual({
@@ -130,7 +130,7 @@ describe(`sending an application by email to a planning office`, () => {
   it("fails without authorization header", async () => {
     await supertest(app)
       .post("/email-submission/southwark")
-      .send({ payload: { sessionId: "123" } })
+      .send({ payload: { sessionId: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49" } })
       .expect(401);
   });
 
@@ -138,12 +138,13 @@ describe(`sending an application by email to a planning office`, () => {
     await supertest(app)
       .post("/email-submission/southwark")
       .set({ Authorization: process.env.HASURA_PLANX_API_KEY! })
-      .send({ payload: { somethingElse: "123" } })
+      .send({
+        payload: { somethingElse: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49" },
+      })
       .expect(400)
       .then((res) => {
-        expect(res.body).toEqual({
-          error: "Missing application payload data to send to email",
-        });
+        expect(res.body).toHaveProperty("issues");
+        expect(res.body).toHaveProperty("name", "ZodError");
       });
   });
 
@@ -167,7 +168,7 @@ describe(`sending an application by email to a planning office`, () => {
     await supertest(app)
       .post("/email-submission/other-council")
       .set({ Authorization: process.env.HASURA_PLANX_API_KEY! })
-      .send({ payload: { sessionId: "123" } })
+      .send({ payload: { sessionId: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49" } })
       .expect(400)
       .then((res) => {
         expect(res.body).toEqual({
@@ -184,13 +185,13 @@ describe(`sending an application by email to a planning office`, () => {
       data: {
         session: null,
       },
-      variables: { id: "123" },
+      variables: { id: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49" },
     });
 
     await supertest(app)
       .post("/email-submission/other-council")
       .set({ Authorization: process.env.HASURA_PLANX_API_KEY! })
-      .send({ payload: { sessionId: "123" } })
+      .send({ payload: { sessionId: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49" } })
       .expect(500)
       .then((res) => {
         expect(res.body.error).toMatch(/Cannot find session/);
@@ -221,7 +222,7 @@ describe(`downloading application data received by email`, () => {
       data: {
         session: { data: { passport: { test: "dummy data" } } },
       },
-      variables: { id: "123" },
+      variables: { id: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49" },
     });
   });
 
@@ -274,12 +275,12 @@ describe(`downloading application data received by email`, () => {
   it("calls addTemplateFilesToZip()", async () => {
     await supertest(app)
       .get(
-        "/download-application-files/123?email=planning.office.example@council.gov.uk&localAuthority=southwark",
+        "/download-application-files/33d373d4-fff2-4ef7-a5f2-2a36e39ccc49?email=planning.office.example@council.gov.uk&localAuthority=southwark",
       )
       .expect(200)
       .then((_res) => {
         expect(mockBuildSubmissionExportZip).toHaveBeenCalledWith({
-          sessionId: "123",
+          sessionId: "33d373d4-fff2-4ef7-a5f2-2a36e39ccc49",
           includeDigitalPlanningJSON: true,
         });
       });
diff --git a/api.planx.uk/modules/send/email/index.ts b/api.planx.uk/modules/send/email/index.ts
index ce7a28dc95..5e5e08f990 100644
--- a/api.planx.uk/modules/send/email/index.ts
+++ b/api.planx.uk/modules/send/email/index.ts
@@ -1,30 +1,24 @@
-import type { NextFunction, Request, Response } from "express";
 import { sendEmail } from "../../../lib/notify/index.js";
 import type { EmailSubmissionNotifyConfig } from "../../../types.js";
 import { markSessionAsSubmitted } from "../../saveAndReturn/service/utils.js";
+import type { SendIntegrationController } from "../types.js";
 import {
   getSessionEmailDetailsById,
   getTeamEmailSettings,
   insertAuditEntry,
 } from "./service.js";
 
-export async function sendToEmail(
-  req: Request,
-  res: Response,
-  next: NextFunction,
-) {
+export const sendToEmail: SendIntegrationController = async (
+  req,
+  res,
+  next,
+) => {
   req.setTimeout(120 * 1000); // Temporary bump to address submission timeouts
 
-  // `/email-submission/:localAuthority` is only called via Hasura's scheduled event webhook, so body is wrapped in a "payload" key
-  const { payload } = req.body;
-  const localAuthority = req.params.localAuthority;
-
-  if (!payload?.sessionId) {
-    return next({
-      status: 400,
-      message: `Missing application payload data to send to email`,
-    });
-  }
+  const {
+    payload: { sessionId },
+  } = res.locals.parsedReq.body;
+  const localAuthority = res.locals.parsedReq.params.localAuthority;
 
   try {
     // Confirm this local authority (aka team) has an email configured in teams.submission_email
@@ -37,16 +31,16 @@ export async function sendToEmail(
     }
 
     // Get the applicant email and flow slug associated with the session
-    const { email, flow } = await getSessionEmailDetailsById(payload.sessionId);
+    const { email, flow } = await getSessionEmailDetailsById(sessionId);
     const flowName = flow.name;
 
     // Prepare email template
     const config: EmailSubmissionNotifyConfig = {
       personalisation: {
         serviceName: flowName,
-        sessionId: payload.sessionId,
+        sessionId,
         applicantEmail: email,
-        downloadLink: `${process.env.API_URL_EXT}/download-application-files/${payload.sessionId}?email=${teamSettings.submissionEmail}&localAuthority=${localAuthority}`,
+        downloadLink: `${process.env.API_URL_EXT}/download-application-files/${sessionId}?email=${teamSettings.submissionEmail}&localAuthority=${localAuthority}`,
         ...teamSettings,
       },
     };
@@ -59,11 +53,11 @@ export async function sendToEmail(
     );
 
     // Mark session as submitted so that reminder and expiry emails are not triggered
-    markSessionAsSubmitted(payload.sessionId);
+    markSessionAsSubmitted(sessionId);
 
     // Create audit table entry, which triggers a Slack notification on `insert` if production
     insertAuditEntry(
-      payload.sessionId,
+      sessionId,
       localAuthority,
       teamSettings.submissionEmail,
       config,
@@ -83,4 +77,4 @@ export async function sendToEmail(
       }`,
     });
   }
-}
+};
diff --git a/api.planx.uk/modules/send/idox/nexus.test.ts b/api.planx.uk/modules/send/idox/nexus.test.ts
index c5c0872de2..b5157f36e5 100644
--- a/api.planx.uk/modules/send/idox/nexus.test.ts
+++ b/api.planx.uk/modules/send/idox/nexus.test.ts
@@ -16,9 +16,8 @@ describe(`sending an application to Idox Nexus`, () => {
       .send({ payload: { somethingElse: "123" } })
       .expect(400)
       .then((res) => {
-        expect(res.body).toEqual({
-          error: "Missing application data to send to Idox Nexus",
-        });
+        expect(res.body).toHaveProperty("issues");
+        expect(res.body).toHaveProperty("name", "ZodError");
       });
   });
 });
diff --git a/api.planx.uk/modules/send/idox/nexus.ts b/api.planx.uk/modules/send/idox/nexus.ts
index 758e1a41b1..7851537562 100644
--- a/api.planx.uk/modules/send/idox/nexus.ts
+++ b/api.planx.uk/modules/send/idox/nexus.ts
@@ -1,6 +1,5 @@
 import type { AxiosRequestConfig } from "axios";
 import axios, { isAxiosError } from "axios";
-import type { NextFunction, Request, Response } from "express";
 import FormData from "form-data";
 import fs from "fs";
 import { gql } from "graphql-request";
@@ -9,6 +8,10 @@ import { Buffer } from "node:buffer";
 import { $api } from "../../../client/index.js";
 import { markSessionAsSubmitted } from "../../saveAndReturn/service/utils.js";
 import { buildSubmissionExportZip } from "../utils/exportZip.js";
+import type {
+  SendIntegrationController,
+  SendIntegrationPayload,
+} from "../types.js";
 
 interface IdoxNexusClient {
   clientId: string;
@@ -40,15 +43,11 @@ interface UniformApplication {
   created_at: string;
 }
 
-interface SendToIdoxNexusPayload {
-  sessionId: string;
-}
-
-export async function sendToIdoxNexus(
-  req: Request,
-  res: Response,
-  next: NextFunction,
-) {
+export const sendToIdoxNexus: SendIntegrationController = async (
+  req,
+  res,
+  next,
+) => {
   /**
    * Submits application data to Idox's Submission API (aka Nexus)
    *
@@ -58,21 +57,14 @@ export async function sendToIdoxNexus(
    */
   req.setTimeout(120 * 1000); // Temporary bump to address submission timeouts
 
-  // `/idox/:localAuthority` is only called via Hasura's scheduled event webhook now, so body is wrapped in a "payload" key
-  const payload: SendToIdoxNexusPayload = req.body.payload;
-  if (!payload?.sessionId) {
-    return next({
-      status: 400,
-      message: "Missing application data to send to Idox Nexus",
-    });
-  }
-
+  const { payload } = res.locals.parsedReq.body;
   // localAuthority is only parsed for audit record, not client-specific
-  const localAuthority = req.params.localAuthority;
+  const localAuthority = res.locals.parsedReq.params.localAuthority;
+
   const idoxNexusClient = getIdoxNexusClient();
 
   // confirm that this session has not already been successfully submitted before proceeding
-  const submittedApp = await checkUniformAuditTable(payload?.sessionId);
+  const submittedApp = await checkUniformAuditTable(payload.sessionId);
   const _isAlreadySubmitted =
     submittedApp?.submissionStatus === "PENDING" && submittedApp?.canDownload;
   // if (isAlreadySubmitted) {
@@ -135,7 +127,7 @@ export async function sendToIdoxNexus(
     });
 
     // Mark session as submitted so that reminder and expiry emails are not triggered
-    markSessionAsSubmitted(payload?.sessionId);
+    markSessionAsSubmitted(payload.sessionId);
 
     return res.status(200).send({
       message: `Successfully created an Idox Nexus submission (${randomOrgId} - ${randomOrg})`,
@@ -151,7 +143,7 @@ export async function sendToIdoxNexus(
       message: `Failed to send to Idox Nexus (${payload.sessionId}): ${errorMessage}`,
     });
   }
-}
+};
 
 /**
  * Query the Uniform audit table to see if we already have an application for this session
@@ -377,7 +369,7 @@ const createUniformApplicationAuditRecord = async ({
   submissionDetails,
 }: {
   idoxSubmissionId: string;
-  payload: SendToIdoxNexusPayload;
+  payload: SendIntegrationPayload;
   localAuthority: string;
   submissionDetails: UniformSubmissionResponse;
 }): Promise<UniformApplication> => {
diff --git a/api.planx.uk/modules/send/routes.ts b/api.planx.uk/modules/send/routes.ts
index bcec19196b..33ab4c8ce3 100644
--- a/api.planx.uk/modules/send/routes.ts
+++ b/api.planx.uk/modules/send/routes.ts
@@ -9,6 +9,7 @@ import { combinedEventsPayloadSchema } from "./createSendEvents/types.js";
 import { downloadApplicationFiles } from "./downloadApplicationFiles/index.js";
 import { sendToS3 } from "./s3/index.js";
 import { sendToIdoxNexus } from "./idox/nexus.js";
+import { sendIntegrationSchema } from "./types.js";
 
 const router = Router();
 
@@ -17,11 +18,37 @@ router.post(
   validate(combinedEventsPayloadSchema),
   createSendEvents,
 );
-router.post("/bops/:localAuthority", useHasuraAuth, sendToBOPS);
-router.post("/uniform/:localAuthority", useHasuraAuth, sendToUniform);
-router.post("/idox/:localAuthority", useHasuraAuth, sendToIdoxNexus);
-router.post("/email-submission/:localAuthority", useHasuraAuth, sendToEmail);
+router.post(
+  "/bops/:localAuthority",
+  useHasuraAuth,
+  validate(sendIntegrationSchema),
+  sendToBOPS,
+);
+router.post(
+  "/uniform/:localAuthority",
+  useHasuraAuth,
+  validate(sendIntegrationSchema),
+  sendToUniform,
+);
+router.post(
+  "/idox/:localAuthority",
+  useHasuraAuth,
+  validate(sendIntegrationSchema),
+  sendToIdoxNexus,
+);
+router.post(
+  "/email-submission/:localAuthority",
+  useHasuraAuth,
+  validate(sendIntegrationSchema),
+  sendToEmail,
+);
+router.post(
+  "/upload-submission/:localAuthority",
+  useHasuraAuth,
+  validate(sendIntegrationSchema),
+  sendToS3,
+);
+
 router.get("/download-application-files/:sessionId", downloadApplicationFiles);
-router.post("/upload-submission/:localAuthority", useHasuraAuth, sendToS3);
 
 export default router;
diff --git a/api.planx.uk/modules/send/s3/index.test.ts b/api.planx.uk/modules/send/s3/index.test.ts
index 01baa00632..5570fb7205 100644
--- a/api.planx.uk/modules/send/s3/index.test.ts
+++ b/api.planx.uk/modules/send/s3/index.test.ts
@@ -77,7 +77,8 @@ describe(`uploading an application to S3`, () => {
       .send({ payload: null })
       .expect(400)
       .then((res) => {
-        expect(res.body.error).toMatch(/Missing application payload/);
+        expect(res.body).toHaveProperty("issues");
+        expect(res.body).toHaveProperty("name", "ZodError");
       });
   });
 
@@ -85,7 +86,9 @@ describe(`uploading an application to S3`, () => {
     await supertest(app)
       .post("/upload-submission/unsupported-team")
       .set({ Authorization: process.env.HASURA_PLANX_API_KEY! })
-      .send({ payload: { sessionId: "123" } })
+      .send({
+        payload: { sessionId: "3188f052-a032-4755-be63-72b0ba497eb6" },
+      })
       .expect(500)
       .then((res) => {
         expect(res.body.error).toMatch(
diff --git a/api.planx.uk/modules/send/s3/index.ts b/api.planx.uk/modules/send/s3/index.ts
index ccd2d2ccd9..6f7186ae8b 100644
--- a/api.planx.uk/modules/send/s3/index.ts
+++ b/api.planx.uk/modules/send/s3/index.ts
@@ -1,6 +1,5 @@
 import type { AxiosRequestConfig } from "axios";
 import axios from "axios";
-import type { NextFunction, Request, Response } from "express";
 import { gql } from "graphql-request";
 
 import { $api } from "../../../client/index.js";
@@ -8,6 +7,7 @@ import type { Passport } from "../../../types.js";
 import { uploadPrivateFile } from "../../file/service/uploadFile.js";
 import { markSessionAsSubmitted } from "../../saveAndReturn/service/utils.js";
 import { isApplicationTypeSupported } from "../utils/helpers.js";
+import type { SendIntegrationController } from "../types.js";
 
 interface CreateS3Application {
   insertS3Application: {
@@ -15,23 +15,15 @@ interface CreateS3Application {
   };
 }
 
-const sendToS3 = async (req: Request, res: Response, next: NextFunction) => {
-  // `/upload-submission/:localAuthority` is only called via Hasura's scheduled event webhook, so body is wrapped in a "payload" key
-  const { payload } = req.body;
-  const localAuthority = req.params.localAuthority;
+const sendToS3: SendIntegrationController = async (_req, res, next) => {
+  const {
+    payload: { sessionId },
+  } = res.locals.parsedReq.body;
+  const localAuthority = res.locals.parsedReq.params.localAuthority;
   const env =
     process.env.APP_ENVIRONMENT === "production" ? "production" : "staging";
 
-  if (!payload?.sessionId) {
-    return next({
-      status: 400,
-      message: `Missing application payload data to send to email`,
-    });
-  }
-
   try {
-    const { sessionId } = payload;
-
     // Fetch integration credentials for this team
     const { powerAutomateWebhookURL, powerAutomateAPIKey } =
       await $api.team.getIntegrations({
diff --git a/api.planx.uk/modules/send/types.ts b/api.planx.uk/modules/send/types.ts
new file mode 100644
index 0000000000..fbf2694d4c
--- /dev/null
+++ b/api.planx.uk/modules/send/types.ts
@@ -0,0 +1,22 @@
+import { z } from "zod";
+import type { ValidatedRequestHandler } from "../../shared/middleware/validate.js";
+
+const payloadSchema = z.object({
+  sessionId: z.string().uuid(),
+});
+
+export type SendIntegrationPayload = z.infer<typeof payloadSchema>;
+
+export const sendIntegrationSchema = z.object({
+  body: z.object({
+    payload: payloadSchema,
+  }),
+  params: z.object({
+    localAuthority: z.string(),
+  }),
+});
+
+export type SendIntegrationController = ValidatedRequestHandler<
+  typeof sendIntegrationSchema,
+  unknown
+>;
diff --git a/api.planx.uk/modules/send/uniform/uniform.test.ts b/api.planx.uk/modules/send/uniform/uniform.test.ts
index 32ffea8812..e698ac31f2 100644
--- a/api.planx.uk/modules/send/uniform/uniform.test.ts
+++ b/api.planx.uk/modules/send/uniform/uniform.test.ts
@@ -16,9 +16,8 @@ describe(`sending an application to uniform`, () => {
       .send({ payload: { somethingElse: "123" } })
       .expect(400)
       .then((res) => {
-        expect(res.body).toEqual({
-          error: "Missing application data to send to Uniform",
-        });
+        expect(res.body).toHaveProperty("issues");
+        expect(res.body).toHaveProperty("name", "ZodError");
       });
   });
 });
diff --git a/api.planx.uk/modules/send/uniform/uniform.ts b/api.planx.uk/modules/send/uniform/uniform.ts
index 795f69cd8c..557ec35f06 100644
--- a/api.planx.uk/modules/send/uniform/uniform.ts
+++ b/api.planx.uk/modules/send/uniform/uniform.ts
@@ -1,6 +1,5 @@
 import type { AxiosRequestConfig } from "axios";
 import axios, { isAxiosError } from "axios";
-import type { NextFunction, Request, Response } from "express";
 import FormData from "form-data";
 import fs from "fs";
 import { gql } from "graphql-request";
@@ -9,6 +8,10 @@ import { Buffer } from "node:buffer";
 import { $api } from "../../../client/index.js";
 import { markSessionAsSubmitted } from "../../saveAndReturn/service/utils.js";
 import { buildSubmissionExportZip } from "../utils/exportZip.js";
+import type {
+  SendIntegrationController,
+  SendIntegrationPayload,
+} from "../types.js";
 
 interface UniformClient {
   clientId: string;
@@ -40,15 +43,11 @@ interface UniformApplication {
   created_at: string;
 }
 
-interface SendToUniformPayload {
-  sessionId: string;
-}
-
-export async function sendToUniform(
-  req: Request,
-  res: Response,
-  next: NextFunction,
-) {
+export const sendToUniform: SendIntegrationController = async (
+  req,
+  res,
+  next,
+) => {
   /**
    * Submits application data to Uniform
    *
@@ -58,16 +57,9 @@ export async function sendToUniform(
    */
   req.setTimeout(120 * 1000); // Temporary bump to address submission timeouts
 
-  // `/uniform/:localAuthority` is only called via Hasura's scheduled event webhook now, so body is wrapped in a "payload" key
-  const payload: SendToUniformPayload = req.body.payload;
-  if (!payload?.sessionId) {
-    return next({
-      status: 400,
-      message: "Missing application data to send to Uniform",
-    });
-  }
+  const { payload } = res.locals.parsedReq.body;
 
-  const localAuthority = req.params.localAuthority;
+  const localAuthority = res.locals.parsedReq.params.localAuthority;
   const uniformClient = getUniformClient(localAuthority);
 
   if (!uniformClient) {
@@ -78,7 +70,7 @@ export async function sendToUniform(
   }
 
   // confirm that this session has not already been successfully submitted before proceeding
-  const submittedApp = await checkUniformAuditTable(payload?.sessionId);
+  const submittedApp = await checkUniformAuditTable(payload.sessionId);
   const isAlreadySubmitted =
     submittedApp?.submissionStatus === "PENDING" && submittedApp?.canDownload;
   if (isAlreadySubmitted) {
@@ -128,7 +120,7 @@ export async function sendToUniform(
     });
 
     // Mark session as submitted so that reminder and expiry emails are not triggered
-    markSessionAsSubmitted(payload?.sessionId);
+    markSessionAsSubmitted(payload.sessionId);
 
     return res.status(200).send({
       message: `Successfully created a Uniform submission`,
@@ -144,7 +136,7 @@ export async function sendToUniform(
       message: `Failed to send to Uniform (${localAuthority}): ${errorMessage}`,
     });
   }
-}
+};
 
 /**
  * Query the Uniform audit table to see if we already have an application for this session
@@ -369,7 +361,7 @@ const createUniformApplicationAuditRecord = async ({
   submissionDetails,
 }: {
   idoxSubmissionId: string;
-  payload: SendToUniformPayload;
+  payload: SendIntegrationPayload;
   localAuthority: string;
   submissionDetails: UniformSubmissionResponse;
 }): Promise<UniformApplication> => {