diff --git a/README.md b/README.md
index bd5efb8e73..6ac6e23c99 100755
--- a/README.md
+++ b/README.md
@@ -63,7 +63,7 @@ npm run dev
 
 After the Docker image has finished building, the application can be accessed at [localhost:5000](localhost:5000).
 
-If there have been no dependency changes in `package.json` or changes in the
+If there are no dependency changes in `package.json` or changes in the
 `src/app/server.ts` file, you can run
 
 ```bash
@@ -75,7 +75,7 @@ only takes ~15 seconds to finish starting up the image.
 
 ### Accessing email locally
 
-We use [MailDev](https://github.com/maildev/maildev) to access emails in the development environment. The MailDev UI can be accessed at [localhost:1080](localhost:1080) when the Docker container is running.
+We use [MailDev](https://github.com/maildev/maildev) to access emails in the development environment. The MailDev UI can be accessed at [localhost:1080](localhost:1080) when the Docker container runs.
 
 ### Environment variables
 
@@ -87,8 +87,8 @@ The following is the order of priority:
 - Environment file
 - Dockerfile
 
-FormSG requires some environment variables in order to function.
-More information about the required environment variables can be seen in
+FormSG requires some environment variables to function.
+More information about the required environment variables are in
 [DEPLOYMENT_SETUP.md](/docs/DEPLOYMENT_SETUP.md).
 
 We provide a [`.template-env`](./.template-env) file with the secrets blanked out. You can copy and
@@ -159,7 +159,7 @@ npm run test-e2e-ci
 
 ## Architecture
 
-An overview of the architecture can be found [here](docs/ARCHITECTURE.md).
+The architecture overview is [here](docs/ARCHITECTURE.md).
 
 ## MongoDB Scripts
 
@@ -167,7 +167,7 @@ Scripts for common tasks in MongoDB can be found [here](docs/MONGODB.md).
 
 ## Contributing
 
-We welcome all contributions, bug reports, bug fixes, documentation improvements, enhancements, and ideas to code open sourced by the Government Technology Agency of Singapore. Contributors should read [CONTRIBUTING.md](CONTRIBUTING.md) and will also be asked to sign a Contributor License Agreement (CLA) in order to ensure that everybody is free to use their contributions.
+We welcome all contributions, bug reports, bug fixes, documentation improvements, enhancements, and ideas to code open sourced by the Government Technology Agency of Singapore. Contributors should read [CONTRIBUTING.md](CONTRIBUTING.md) and will also be asked to sign a Contributor License Agreement (CLA) to ensure that everybody is free to use their contributions.
 
 ## Support
 
diff --git a/src/app/modules/auth/__tests__/auth.controller.spec.ts b/src/app/modules/auth/__tests__/auth.controller.spec.ts
index f5dd798968..a142751310 100644
--- a/src/app/modules/auth/__tests__/auth.controller.spec.ts
+++ b/src/app/modules/auth/__tests__/auth.controller.spec.ts
@@ -42,7 +42,7 @@ describe('auth.controller', () => {
       )
 
       // Act
-      await AuthController.handleCheckUser(MOCK_REQ, mockRes, jest.fn())
+      await AuthController._handleCheckUser(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.sendStatus).toBeCalledWith(200)
@@ -57,7 +57,7 @@ describe('auth.controller', () => {
       )
 
       // Act
-      await AuthController.handleCheckUser(MOCK_REQ, mockRes, jest.fn())
+      await AuthController._handleCheckUser(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(401)
@@ -82,7 +82,7 @@ describe('auth.controller', () => {
       MockMailService.sendLoginOtp.mockReturnValueOnce(okAsync(true))
 
       // Act
-      await AuthController.handleLoginSendOtp(MOCK_REQ, mockRes, jest.fn())
+      await AuthController._handleLoginSendOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(200)
@@ -101,7 +101,7 @@ describe('auth.controller', () => {
       )
 
       // Act
-      await AuthController.handleLoginSendOtp(MOCK_REQ, mockRes, jest.fn())
+      await AuthController._handleLoginSendOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(401)
@@ -120,7 +120,7 @@ describe('auth.controller', () => {
       )
 
       // Act
-      await AuthController.handleLoginSendOtp(MOCK_REQ, mockRes, jest.fn())
+      await AuthController._handleLoginSendOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(500)
@@ -146,7 +146,7 @@ describe('auth.controller', () => {
       )
 
       // Act
-      await AuthController.handleLoginSendOtp(MOCK_REQ, mockRes, jest.fn())
+      await AuthController._handleLoginSendOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(500)
@@ -183,7 +183,7 @@ describe('auth.controller', () => {
       MockUserService.retrieveUser.mockReturnValueOnce(okAsync(mockUser))
 
       // Act
-      await AuthController.handleLoginVerifyOtp(MOCK_REQ, mockRes, jest.fn())
+      await AuthController._handleLoginVerifyOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(200)
@@ -199,7 +199,7 @@ describe('auth.controller', () => {
       )
 
       // Act
-      await AuthController.handleLoginVerifyOtp(MOCK_REQ, mockRes, jest.fn())
+      await AuthController._handleLoginVerifyOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(401)
@@ -219,7 +219,7 @@ describe('auth.controller', () => {
       )
 
       // Act
-      await AuthController.handleLoginVerifyOtp(MOCK_REQ, mockRes, jest.fn())
+      await AuthController._handleLoginVerifyOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(422)
@@ -241,7 +241,7 @@ describe('auth.controller', () => {
       )
 
       // Act
-      await AuthController.handleLoginVerifyOtp(MOCK_REQ, mockRes, jest.fn())
+      await AuthController._handleLoginVerifyOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(500)
@@ -265,7 +265,7 @@ describe('auth.controller', () => {
       )
 
       // Act
-      await AuthController.handleLoginVerifyOtp(MOCK_REQ, mockRes, jest.fn())
+      await AuthController._handleLoginVerifyOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(500)
diff --git a/src/app/modules/auth/auth.controller.ts b/src/app/modules/auth/auth.controller.ts
index 5d280baeba..188c8f3524 100644
--- a/src/app/modules/auth/auth.controller.ts
+++ b/src/app/modules/auth/auth.controller.ts
@@ -8,19 +8,18 @@ import { createReqMeta, getRequestIp } from '../../utils/request'
 import { ControllerHandler } from '../core/core.types'
 import * as UserService from '../user/user.service'
 
+import {
+  validateCheckUserParams,
+  validateLoginSendOtpParams,
+  validateVerifyOtpParams,
+} from './auth.middlewares'
 import * as AuthService from './auth.service'
 import { SessionUser } from './auth.types'
 import { mapRouteError } from './auth.utils'
 
 const logger = createLoggerWithLabel(module)
 
-/**
- * Handler for GET /auth/checkuser endpoint.
- * @returns 500 when there was an error validating body.email
- * @returns 401 when domain of body.email is invalid
- * @returns 200 if domain of body.email is valid
- */
-export const handleCheckUser: ControllerHandler<
+export const _handleCheckUser: ControllerHandler<
   unknown,
   string,
   { email: string }
@@ -46,12 +45,17 @@ export const handleCheckUser: ControllerHandler<
 }
 
 /**
- * Handler for POST /auth/sendotp endpoint.
- * @return 200 when OTP has been been successfully sent
- * @return 401 when email domain is invalid
- * @return 500 when unknown errors occurs during generate OTP, or create/send the email that delivers the OTP to the user's email address
+ * Handler for GET /auth/checkuser endpoint.
+ * @returns 500 when there was an error validating body.email
+ * @returns 401 when domain of body.email is invalid
+ * @returns 200 if domain of body.email is valid
  */
-export const handleLoginSendOtp: ControllerHandler<
+export const handleCheckUser = [
+  validateCheckUserParams,
+  _handleCheckUser,
+] as ControllerHandler[]
+
+export const _handleLoginSendOtp: ControllerHandler<
   unknown,
   { message: string } | string,
   { email: string }
@@ -103,6 +107,17 @@ export const handleLoginSendOtp: ControllerHandler<
   )
 }
 
+/**
+ * Handler for POST /auth/sendotp endpoint.
+ * @return 200 when OTP has been been successfully sent
+ * @return 401 when email domain is invalid
+ * @return 500 when unknown errors occurs during generate OTP, or create/send the email that delivers the OTP to the user's email address
+ */
+export const handleLoginSendOtp = [
+  validateLoginSendOtpParams,
+  _handleLoginSendOtp,
+] as ControllerHandler[]
+
 /**
  * Handler for POST /auth/verifyotp endpoint.
  * @returns 200 when user has successfully logged in, with session cookie set
@@ -110,7 +125,7 @@ export const handleLoginSendOtp: ControllerHandler<
  * @returns 422 when the OTP is invalid
  * @returns 500 when error occurred whilst verifying the OTP
  */
-export const handleLoginVerifyOtp: ControllerHandler<
+export const _handleLoginVerifyOtp: ControllerHandler<
   unknown,
   string | SessionUser,
   { email: string; otp: string }
@@ -185,6 +200,11 @@ export const handleLoginVerifyOtp: ControllerHandler<
   )
 }
 
+export const handleLoginVerifyOtp = [
+  validateVerifyOtpParams,
+  _handleLoginVerifyOtp,
+] as ControllerHandler[]
+
 export const handleSignout: ControllerHandler = async (req, res) => {
   if (!req.session || isEmpty(req.session)) {
     logger.error({
diff --git a/src/app/modules/auth/auth.middlewares.ts b/src/app/modules/auth/auth.middlewares.ts
index d61ad462aa..af232735b1 100644
--- a/src/app/modules/auth/auth.middlewares.ts
+++ b/src/app/modules/auth/auth.middlewares.ts
@@ -1,3 +1,4 @@
+import { celebrate, Joi, Segments } from 'celebrate'
 import { AuthedSessionData } from 'express-session'
 import { StatusCodes } from 'http-status-codes'
 
@@ -57,3 +58,37 @@ export const logAdminAction: ControllerHandler<{ formId: string }> = async (
 
   return next()
 }
+
+export const validateCheckUserParams = celebrate({
+  [Segments.BODY]: Joi.object().keys({
+    email: Joi.string()
+      .required()
+      .email()
+      .message('Please enter a valid email')
+      .lowercase(),
+  }),
+})
+
+export const validateLoginSendOtpParams = celebrate({
+  [Segments.BODY]: Joi.object().keys({
+    email: Joi.string()
+      .required()
+      .email()
+      .message('Please enter a valid email')
+      .lowercase(),
+  }),
+})
+
+export const validateVerifyOtpParams = celebrate({
+  [Segments.BODY]: Joi.object().keys({
+    email: Joi.string()
+      .required()
+      .email()
+      .message('Please enter a valid email')
+      .lowercase(),
+    otp: Joi.string()
+      .required()
+      .regex(/^\d{6}$/)
+      .message('Please enter a valid OTP'),
+  }),
+})
diff --git a/src/app/modules/auth/auth.routes.ts b/src/app/modules/auth/auth.routes.ts
index b47a532017..ffa645bbc3 100644
--- a/src/app/modules/auth/auth.routes.ts
+++ b/src/app/modules/auth/auth.routes.ts
@@ -1,4 +1,3 @@
-import { celebrate, Joi, Segments } from 'celebrate'
 import { Router } from 'express'
 
 import { rateLimitConfig } from '../../config/config'
@@ -16,19 +15,7 @@ export const AuthRouter = Router()
  * @return 200 when email domain is valid
  * @return 401 when email domain is invalid
  */
-AuthRouter.post(
-  '/checkuser',
-  celebrate({
-    [Segments.BODY]: Joi.object().keys({
-      email: Joi.string()
-        .required()
-        .email()
-        .message('Please enter a valid email')
-        .lowercase(),
-    }),
-  }),
-  AuthController.handleCheckUser,
-)
+AuthRouter.post('/checkuser', AuthController.handleCheckUser)
 
 /**
  * Send a one-time password (OTP) to the specified email address
@@ -45,15 +32,6 @@ AuthRouter.post(
 AuthRouter.post(
   '/sendotp',
   limitRate({ max: rateLimitConfig.sendAuthOtp }),
-  celebrate({
-    [Segments.BODY]: Joi.object().keys({
-      email: Joi.string()
-        .required()
-        .email()
-        .message('Please enter a valid email')
-        .lowercase(),
-    }),
-  }),
   AuthController.handleLoginSendOtp,
 )
 
@@ -70,23 +48,7 @@ AuthRouter.post(
  * @returns 422 when the OTP is invalid
  * @returns 500 when error occurred whilst verifying the OTP
  */
-AuthRouter.post(
-  '/verifyotp',
-  celebrate({
-    [Segments.BODY]: Joi.object().keys({
-      email: Joi.string()
-        .required()
-        .email()
-        .message('Please enter a valid email')
-        .lowercase(),
-      otp: Joi.string()
-        .required()
-        .regex(/^\d{6}$/)
-        .message('Please enter a valid OTP'),
-    }),
-  }),
-  AuthController.handleLoginVerifyOtp,
-)
+AuthRouter.post('/verifyotp', AuthController.handleLoginVerifyOtp)
 
 /**
  * Sign the user out of the session by clearing the relevant session cookie
diff --git a/src/app/modules/billing/__tests__/billing.controller.spec.ts b/src/app/modules/billing/__tests__/billing.controller.spec.ts
index dd11890b61..4dc500bb57 100644
--- a/src/app/modules/billing/__tests__/billing.controller.spec.ts
+++ b/src/app/modules/billing/__tests__/billing.controller.spec.ts
@@ -68,7 +68,7 @@ describe('billing.controller', () => {
       )
 
       // Act
-      await BillingController.handleGetBillInfo(MOCK_REQ, mockRes, jest.fn())
+      await BillingController._handleGetBillInfo(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(MockBillingService.getSpLoginStats).toHaveBeenCalledWith(
@@ -86,7 +86,7 @@ describe('billing.controller', () => {
       )
 
       // Act
-      await BillingController.handleGetBillInfo(MOCK_REQ, mockRes, jest.fn())
+      await BillingController._handleGetBillInfo(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(MockBillingService.getSpLoginStats).toHaveBeenCalledWith(
diff --git a/src/app/modules/billing/billing.controller.ts b/src/app/modules/billing/billing.controller.ts
index 71f4af4fea..ade5f6bdcf 100644
--- a/src/app/modules/billing/billing.controller.ts
+++ b/src/app/modules/billing/billing.controller.ts
@@ -11,19 +11,12 @@ import { createLoggerWithLabel } from '../../config/logger'
 import { createReqMeta } from '../../utils/request'
 import { ControllerHandler } from '../core/core.types'
 
+import { validateGetBillingInfoParams } from './billing.middlewares'
 import * as BillingService from './billing.service'
 
 const logger = createLoggerWithLabel(module)
 
-/**
- * Handler for GET /billing endpoint.
- * @security session
- *
- * @return 200 with login statistics when query is valid
- * @return 401 when request does not contain a user session
- * @return 500 when error occurs whilst querying database
- */
-export const handleGetBillInfo: ControllerHandler<
+export const _handleGetBillInfo: ControllerHandler<
   unknown,
   ErrorDto | BillingInfoDto,
   unknown,
@@ -72,3 +65,16 @@ export const handleGetBillInfo: ControllerHandler<
     loginStats: loginStatsResult.value,
   })
 }
+
+/**
+ * Handler for GET /billing endpoint.
+ * @security session
+ *
+ * @return 200 with login statistics when query is valid
+ * @return 401 when request does not contain a user session
+ * @return 500 when error occurs whilst querying database
+ */
+export const handleGetBillInfo = [
+  validateGetBillingInfoParams,
+  _handleGetBillInfo,
+] as ControllerHandler[]
diff --git a/src/app/modules/billing/billing.middlewares.ts b/src/app/modules/billing/billing.middlewares.ts
new file mode 100644
index 0000000000..76c1e742c0
--- /dev/null
+++ b/src/app/modules/billing/billing.middlewares.ts
@@ -0,0 +1,9 @@
+import { celebrate, Joi, Segments } from 'celebrate'
+
+export const validateGetBillingInfoParams = celebrate({
+  [Segments.QUERY]: Joi.object({
+    esrvcId: Joi.string().required(),
+    yr: Joi.number().integer().min(2019).required(),
+    mth: Joi.number().integer().min(0).max(11).required(),
+  }),
+})
diff --git a/src/app/modules/billing/billing.routes.ts b/src/app/modules/billing/billing.routes.ts
index ca53f8b546..afa71877c2 100644
--- a/src/app/modules/billing/billing.routes.ts
+++ b/src/app/modules/billing/billing.routes.ts
@@ -1,4 +1,3 @@
-import { celebrate, Joi, Segments } from 'celebrate'
 import { Router } from 'express'
 
 import { withUserAuthentication } from '../auth/auth.middlewares'
@@ -22,14 +21,4 @@ BillingRouter.use(withUserAuthentication)
  * @return 401 when request does not contain a user session
  * @return 500 when error occurs whilst querying database
  */
-BillingRouter.get(
-  '/',
-  celebrate({
-    [Segments.QUERY]: Joi.object({
-      esrvcId: Joi.string().required(),
-      yr: Joi.number().integer().min(2019).required(),
-      mth: Joi.number().integer().min(0).max(11).required(),
-    }),
-  }),
-  BillingController.handleGetBillInfo,
-)
+BillingRouter.get('/', BillingController.handleGetBillInfo)
diff --git a/src/app/modules/examples/__tests__/examples.controller.spec.ts b/src/app/modules/examples/__tests__/examples.controller.spec.ts
index dba66283d4..e7ea870910 100644
--- a/src/app/modules/examples/__tests__/examples.controller.spec.ts
+++ b/src/app/modules/examples/__tests__/examples.controller.spec.ts
@@ -42,7 +42,7 @@ describe('examples.controller', () => {
       )
 
       // Act
-      await ExamplesController.handleGetExamples(MOCK_REQ, mockRes, jest.fn())
+      await ExamplesController._handleGetExamples(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(MockExamplesService.getExampleForms).toHaveBeenCalledWith(
@@ -61,7 +61,7 @@ describe('examples.controller', () => {
       )
 
       // Act
-      await ExamplesController.handleGetExamples(MOCK_REQ, mockRes, jest.fn())
+      await ExamplesController._handleGetExamples(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(MockExamplesService.getExampleForms).toHaveBeenCalledWith(
diff --git a/src/app/modules/examples/examples.controller.ts b/src/app/modules/examples/examples.controller.ts
index 533b1cdceb..43407637bd 100644
--- a/src/app/modules/examples/examples.controller.ts
+++ b/src/app/modules/examples/examples.controller.ts
@@ -10,6 +10,7 @@ import { createLoggerWithLabel } from '../../config/logger'
 import { createReqMeta } from '../../utils/request'
 import { ControllerHandler } from '../core/core.types'
 
+import { validateGetExamplesParams } from './examples.middlewares'
 import * as ExamplesService from './examples.service'
 import { mapRouteError } from './examples.utils'
 
@@ -23,7 +24,7 @@ const logger = createLoggerWithLabel(module)
  * @returns 401 when user does not exist in session
  * @returns 500 when error occurs whilst querying the database
  */
-export const handleGetExamples: ControllerHandler<
+export const _handleGetExamples: ControllerHandler<
   unknown,
   ErrorDto | ExampleFormsResult,
   unknown,
@@ -46,6 +47,11 @@ export const handleGetExamples: ControllerHandler<
     })
 }
 
+export const handleGetExamples = [
+  validateGetExamplesParams,
+  _handleGetExamples,
+] as ControllerHandler[]
+
 /**
  * Handler for GET /examples/:formId endpoint.
  * @security session
diff --git a/src/app/modules/examples/examples.middlewares.ts b/src/app/modules/examples/examples.middlewares.ts
new file mode 100644
index 0000000000..4df50b44fb
--- /dev/null
+++ b/src/app/modules/examples/examples.middlewares.ts
@@ -0,0 +1,12 @@
+import { celebrate, Joi, Segments } from 'celebrate'
+
+export const validateGetExamplesParams = celebrate({
+  [Segments.QUERY]: Joi.object().keys({
+    pageNo: Joi.number().min(0).required(),
+    agency: Joi.string()
+      .regex(/^[0-9a-fA-F]{24}$/)
+      .allow(''),
+    searchTerm: Joi.string().allow(''),
+    shouldGetTotalNumResults: Joi.boolean().default(false),
+  }),
+})
diff --git a/src/app/modules/examples/examples.routes.ts b/src/app/modules/examples/examples.routes.ts
index 611a1547b9..313cff72e6 100644
--- a/src/app/modules/examples/examples.routes.ts
+++ b/src/app/modules/examples/examples.routes.ts
@@ -1,4 +1,3 @@
-import { celebrate, Joi, Segments } from 'celebrate'
 import { Router } from 'express'
 
 import { withUserAuthentication } from '../auth/auth.middlewares'
@@ -22,20 +21,7 @@ ExamplesRouter.use(withUserAuthentication)
  * @returns 401 when user does not exist in session
  * @returns 500 when error occurs whilst querying the database
  */
-ExamplesRouter.get(
-  '/',
-  celebrate({
-    [Segments.QUERY]: Joi.object().keys({
-      pageNo: Joi.number().min(0).required(),
-      agency: Joi.string()
-        .regex(/^[0-9a-fA-F]{24}$/)
-        .allow(''),
-      searchTerm: Joi.string().allow(''),
-      shouldGetTotalNumResults: Joi.boolean().default(false),
-    }),
-  }),
-  ExamplesController.handleGetExamples,
-)
+ExamplesRouter.get('/', ExamplesController.handleGetExamples)
 
 /**
  * Returns example information for the form that is referenced by the given
diff --git a/src/app/modules/form/admin-form/__tests__/admin-form.controller.spec.ts b/src/app/modules/form/admin-form/__tests__/admin-form.controller.spec.ts
index e922e14019..6ba7072fe1 100644
--- a/src/app/modules/form/admin-form/__tests__/admin-form.controller.spec.ts
+++ b/src/app/modules/form/admin-form/__tests__/admin-form.controller.spec.ts
@@ -4525,7 +4525,7 @@ describe('admin-form.controller', () => {
       )
 
       // Act
-      await AdminFormController.handleUpdateSettings(
+      await AdminFormController._handleUpdateSettings(
         MOCK_REQ,
         mockRes,
         jest.fn(),
@@ -4564,7 +4564,7 @@ describe('admin-form.controller', () => {
       )
 
       // Act
-      await AdminFormController.handleUpdateSettings(
+      await AdminFormController._handleUpdateSettings(
         MOCK_REQ,
         mockRes,
         jest.fn(),
@@ -4598,7 +4598,7 @@ describe('admin-form.controller', () => {
       )
 
       // Act
-      await AdminFormController.handleUpdateSettings(
+      await AdminFormController._handleUpdateSettings(
         MOCK_REQ,
         mockRes,
         jest.fn(),
@@ -4636,7 +4636,7 @@ describe('admin-form.controller', () => {
       )
 
       // Act
-      await AdminFormController.handleUpdateSettings(
+      await AdminFormController._handleUpdateSettings(
         MOCK_REQ,
         mockRes,
         jest.fn(),
@@ -4673,7 +4673,7 @@ describe('admin-form.controller', () => {
       )
 
       // Act
-      await AdminFormController.handleUpdateSettings(
+      await AdminFormController._handleUpdateSettings(
         MOCK_REQ,
         mockRes,
         jest.fn(),
@@ -4711,7 +4711,7 @@ describe('admin-form.controller', () => {
       )
 
       // Act
-      await AdminFormController.handleUpdateSettings(
+      await AdminFormController._handleUpdateSettings(
         MOCK_REQ,
         mockRes,
         jest.fn(),
@@ -4752,7 +4752,7 @@ describe('admin-form.controller', () => {
       )
 
       // Act
-      await AdminFormController.handleUpdateSettings(
+      await AdminFormController._handleUpdateSettings(
         MOCK_REQ,
         mockRes,
         jest.fn(),
@@ -4786,7 +4786,7 @@ describe('admin-form.controller', () => {
       )
 
       // Act
-      await AdminFormController.handleUpdateSettings(
+      await AdminFormController._handleUpdateSettings(
         MOCK_REQ,
         mockRes,
         jest.fn(),
@@ -4820,7 +4820,7 @@ describe('admin-form.controller', () => {
       )
 
       // Act
-      await AdminFormController.handleUpdateSettings(
+      await AdminFormController._handleUpdateSettings(
         MOCK_REQ,
         mockRes,
         jest.fn(),
diff --git a/src/app/modules/form/admin-form/admin-form.controller.ts b/src/app/modules/form/admin-form/admin-form.controller.ts
index 35222f0f19..024154f7c5 100644
--- a/src/app/modules/form/admin-form/admin-form.controller.ts
+++ b/src/app/modules/form/admin-form/admin-form.controller.ts
@@ -88,6 +88,7 @@ import {
   PREVIEW_SINGPASS_UINFIN,
 } from './admin-form.constants'
 import { EditFieldError } from './admin-form.errors'
+import { updateSettingsValidator } from './admin-form.middlewares'
 import * as AdminFormService from './admin-form.service'
 import { PermissionLevel } from './admin-form.types'
 import { mapRouteError } from './admin-form.utils'
@@ -1247,22 +1248,7 @@ export const handleDuplicateFormField: ControllerHandler<
     })
 }
 
-/**
- * Handler for PATCH /forms/:formId/settings.
- * @security session
- *
- * @returns 200 with updated form settings
- * @returns 400 when body is malformed; can happen when email parameter is passed for encrypt-mode forms
- * @returns 403 when current user does not have permissions to update form settings
- * @returns 404 when form to update settings for cannot be found
- * @returns 409 when saving form settings incurs a conflict in the database
- * @returns 410 when updating settings for archived form
- * @returns 413 when updating settings causes form to be too large to be saved in the database
- * @returns 422 when an invalid settings update is attempted on the form
- * @returns 422 when user in session cannot be retrieved from the database
- * @returns 500 when database error occurs
- */
-export const handleUpdateSettings: ControllerHandler<
+export const _handleUpdateSettings: ControllerHandler<
   { formId: string },
   FormSettings | ErrorDto,
   SettingsUpdateDto
@@ -1302,6 +1288,26 @@ export const handleUpdateSettings: ControllerHandler<
     })
 }
 
+/**
+ * Handler for PATCH /forms/:formId/settings.
+ * @security session
+ *
+ * @returns 200 with updated form settings
+ * @returns 400 when body is malformed; can happen when email parameter is passed for encrypt-mode forms
+ * @returns 403 when current user does not have permissions to update form settings
+ * @returns 404 when form to update settings for cannot be found
+ * @returns 409 when saving form settings incurs a conflict in the database
+ * @returns 410 when updating settings for archived form
+ * @returns 413 when updating settings causes form to be too large to be saved in the database
+ * @returns 422 when an invalid settings update is attempted on the form
+ * @returns 422 when user in session cannot be retrieved from the database
+ * @returns 500 when database error occurs
+ */
+export const handleUpdateSettings = [
+  updateSettingsValidator,
+  _handleUpdateSettings,
+] as ControllerHandler[]
+
 /**
  * NOTE: Exported for testing.
  * Private handler for PUT /forms/:formId/fields/:fieldId
diff --git a/src/app/modules/form/admin-form/admin-form.middlewares.ts b/src/app/modules/form/admin-form/admin-form.middlewares.ts
new file mode 100644
index 0000000000..320b73b76c
--- /dev/null
+++ b/src/app/modules/form/admin-form/admin-form.middlewares.ts
@@ -0,0 +1,30 @@
+import { celebrate, Joi, Segments } from 'celebrate'
+
+import {
+  FormAuthType,
+  FormStatus,
+  SettingsUpdateDto,
+} from '../../../../../shared/types'
+
+/**
+ * Joi validator for PATCH /forms/:formId/settings route.
+ */
+export const updateSettingsValidator = celebrate({
+  [Segments.BODY]: Joi.object<SettingsUpdateDto>({
+    authType: Joi.string().valid(...Object.values(FormAuthType)),
+    emails: Joi.alternatives().try(
+      Joi.array().items(Joi.string().email()),
+      Joi.string().email({ multiple: true }),
+    ),
+    esrvcId: Joi.string().allow(''),
+    hasCaptcha: Joi.boolean(),
+    inactiveMessage: Joi.string(),
+    status: Joi.string().valid(...Object.values(FormStatus)),
+    submissionLimit: Joi.number().allow(null),
+    title: Joi.string(),
+    webhook: Joi.object({
+      url: Joi.string().uri().allow(''),
+      isRetryEnabled: Joi.boolean(),
+    }).min(1),
+  }).min(1),
+})
diff --git a/src/app/modules/frontend/__tests__/frontend.controller.spec.ts b/src/app/modules/frontend/__tests__/frontend.controller.spec.ts
index da32eb2d63..a80076dc32 100644
--- a/src/app/modules/frontend/__tests__/frontend.controller.spec.ts
+++ b/src/app/modules/frontend/__tests__/frontend.controller.spec.ts
@@ -77,7 +77,7 @@ describe('frontend.server.controller', () => {
         'window.location.hash = "#!/formId?fieldId1=abc&fieldId2=&lt;&gt;&#39;&#34;'
       // Note this is different from mockReqModified.query.redirectPath as
       // there are html-encoded characters
-      FrontendServerController.generateRedirectUrl(
+      FrontendServerController._generateRedirectUrl(
         mockReqModified,
         mockRes,
         jest.fn(),
@@ -89,7 +89,7 @@ describe('frontend.server.controller', () => {
       expect(mockRes.status).toHaveBeenCalledWith(StatusCodes.OK)
     })
     it('should return BAD_REQUEST if the request is not valid', () => {
-      FrontendServerController.generateRedirectUrl(
+      FrontendServerController._generateRedirectUrl(
         // @ts-ignore
         mockBadReq,
         mockRes,
diff --git a/src/app/modules/frontend/frontend.controller.ts b/src/app/modules/frontend/frontend.controller.ts
index 3268e9552d..7af36f345c 100644
--- a/src/app/modules/frontend/frontend.controller.ts
+++ b/src/app/modules/frontend/frontend.controller.ts
@@ -5,6 +5,8 @@ import { createLoggerWithLabel } from '../../config/logger'
 import { createReqMeta } from '../../utils/request'
 import { ControllerHandler } from '../core/core.types'
 
+import { validateGenerateRedirectParams } from './frontend.middlewares'
+
 const logger = createLoggerWithLabel(module)
 
 /**
@@ -81,7 +83,7 @@ export const addEnvVarData: ControllerHandler<unknown, { message: string }> = (
  * @param res - Express response object
  * @returns Templated Javascript code for the frontend that redirects to specific form url
  */
-export const generateRedirectUrl: ControllerHandler<
+export const _generateRedirectUrl: ControllerHandler<
   unknown,
   string | { message: string },
   unknown,
@@ -115,6 +117,11 @@ export const generateRedirectUrl: ControllerHandler<
   }
 }
 
+export const generateRedirectUrl = [
+  validateGenerateRedirectParams,
+  _generateRedirectUrl,
+] as ControllerHandler[]
+
 // Duplicated here since the feature manager is being deprecated.
 // TODO (#2147): delete this.
 enum FeatureNames {
diff --git a/src/app/modules/frontend/frontend.middlewares.ts b/src/app/modules/frontend/frontend.middlewares.ts
new file mode 100644
index 0000000000..f1a7699724
--- /dev/null
+++ b/src/app/modules/frontend/frontend.middlewares.ts
@@ -0,0 +1,9 @@
+import { celebrate, Joi, Segments } from 'celebrate'
+
+export const validateGenerateRedirectParams = celebrate({
+  [Segments.QUERY]: {
+    redirectPath: Joi.string()
+      .regex(/^[a-fA-F0-9]{24}(\/(preview|template|use-template))?/)
+      .required(),
+  },
+})
diff --git a/src/app/modules/frontend/frontend.routes.ts b/src/app/modules/frontend/frontend.routes.ts
index 0fc0bdfddd..d0f0879220 100644
--- a/src/app/modules/frontend/frontend.routes.ts
+++ b/src/app/modules/frontend/frontend.routes.ts
@@ -1,4 +1,3 @@
-import { celebrate, Joi, Segments } from 'celebrate'
 import { Router } from 'express'
 
 import * as FrontendServerController from './frontend.controller'
@@ -40,14 +39,4 @@ FrontendRouter.get('/features', FrontendServerController.showFeaturesStates)
  * @return 200 when redirect code is  successful
  * @return 400 when redirect code fails
  */
-FrontendRouter.get(
-  '/redirect',
-  celebrate({
-    [Segments.QUERY]: {
-      redirectPath: Joi.string()
-        .regex(/^[a-fA-F0-9]{24}(\/(preview|template|use-template))?/)
-        .required(),
-    },
-  }),
-  FrontendServerController.generateRedirectUrl,
-)
+FrontendRouter.get('/redirect', FrontendServerController.generateRedirectUrl)
diff --git a/src/app/modules/user/__tests__/user.controller.spec.ts b/src/app/modules/user/__tests__/user.controller.spec.ts
index e081c0bf6a..038486391f 100644
--- a/src/app/modules/user/__tests__/user.controller.spec.ts
+++ b/src/app/modules/user/__tests__/user.controller.spec.ts
@@ -51,7 +51,7 @@ describe('user.controller', () => {
       MockSmsFactory.sendAdminContactOtp.mockReturnValueOnce(okAsync(true))
 
       // Act
-      await UserController.handleContactSendOtp(MOCK_REQ, mockRes, jest.fn())
+      await UserController._handleContactSendOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       // Check passed in params.
@@ -78,7 +78,7 @@ describe('user.controller', () => {
       const mockRes = expressHandler.mockResponse()
 
       // Act
-      await UserController.handleContactSendOtp(
+      await UserController._handleContactSendOtp(
         reqWithoutSession,
         mockRes,
         jest.fn(),
@@ -109,7 +109,7 @@ describe('user.controller', () => {
       const mockRes = expressHandler.mockResponse()
 
       // Act
-      await UserController.handleContactSendOtp(
+      await UserController._handleContactSendOtp(
         reqWithDiffUserParam,
         mockRes,
         jest.fn(),
@@ -137,7 +137,7 @@ describe('user.controller', () => {
       )
 
       // Act
-      await UserController.handleContactSendOtp(MOCK_REQ, mockRes, jest.fn())
+      await UserController._handleContactSendOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(422)
@@ -158,7 +158,7 @@ describe('user.controller', () => {
       )
 
       // Act
-      await UserController.handleContactSendOtp(MOCK_REQ, mockRes, jest.fn())
+      await UserController._handleContactSendOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(500)
@@ -200,7 +200,7 @@ describe('user.controller', () => {
       )
 
       // Act
-      await UserController.handleContactVerifyOtp(MOCK_REQ, mockRes, jest.fn())
+      await UserController._handleContactVerifyOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       // Expect services to be called with correct arguments.
@@ -229,7 +229,7 @@ describe('user.controller', () => {
       const mockRes = expressHandler.mockResponse()
 
       // Act
-      await UserController.handleContactVerifyOtp(
+      await UserController._handleContactVerifyOtp(
         reqWithoutSession,
         mockRes,
         jest.fn(),
@@ -261,7 +261,7 @@ describe('user.controller', () => {
       const mockRes = expressHandler.mockResponse()
 
       // Act
-      await UserController.handleContactVerifyOtp(
+      await UserController._handleContactVerifyOtp(
         reqWithDiffUserParam,
         mockRes,
         jest.fn(),
@@ -289,7 +289,7 @@ describe('user.controller', () => {
       )
 
       // Act
-      await UserController.handleContactVerifyOtp(MOCK_REQ, mockRes, jest.fn())
+      await UserController._handleContactVerifyOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(500)
@@ -309,7 +309,7 @@ describe('user.controller', () => {
       )
 
       // Act
-      await UserController.handleContactVerifyOtp(MOCK_REQ, mockRes, jest.fn())
+      await UserController._handleContactVerifyOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(401)
@@ -329,7 +329,7 @@ describe('user.controller', () => {
       )
 
       // Act
-      await UserController.handleContactVerifyOtp(MOCK_REQ, mockRes, jest.fn())
+      await UserController._handleContactVerifyOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(422)
@@ -349,7 +349,7 @@ describe('user.controller', () => {
       )
 
       // Act
-      await UserController.handleContactVerifyOtp(MOCK_REQ, mockRes, jest.fn())
+      await UserController._handleContactVerifyOtp(MOCK_REQ, mockRes, jest.fn())
 
       // Assert
       expect(mockRes.status).toBeCalledWith(500)
diff --git a/src/app/modules/user/user.controller.ts b/src/app/modules/user/user.controller.ts
index a598ee7747..8920fe906d 100644
--- a/src/app/modules/user/user.controller.ts
+++ b/src/app/modules/user/user.controller.ts
@@ -7,6 +7,10 @@ import { getRequestIp } from '../../utils/request'
 import { getUserIdFromSession } from '../auth/auth.utils'
 import { ControllerHandler } from '../core/core.types'
 
+import {
+  validateContactOtpVerificationParams,
+  validateContactSendOtpParams,
+} from './user.middleware'
 import {
   createContactOtp,
   getPopulatedUserById,
@@ -17,16 +21,7 @@ import { mapRouteError } from './user.utils'
 
 const logger = createLoggerWithLabel(module)
 
-/**
- * Generates an OTP and sends the OTP to the given contact in request body.
- * @route POST /contact/otp/generate
- * @returns 200 if OTP was successfully sent
- * @returns 401 if user id does not match current session user or if user is not currently logged in
- * @returns 422 on OTP creation or SMS send failure
- * @returns 422 if user id does not exist in the database
- * @returns 500 if database errors occurs
- */
-export const handleContactSendOtp: ControllerHandler<
+export const _handleContactSendOtp: ControllerHandler<
   unknown,
   string,
   { contact: string; userId: string }
@@ -92,15 +87,20 @@ export const handleContactSendOtp: ControllerHandler<
 }
 
 /**
- * Verifies given OTP with the hashed OTP data, and updates the user's contact
- * number if the hash matches.
- * @route POST /contact/otp/verify
- * @returns 200 when user contact update success
+ * Generates an OTP and sends the OTP to the given contact in request body.
+ * @route POST /contact/otp/generate
+ * @returns 200 if OTP was successfully sent
  * @returns 401 if user id does not match current session user or if user is not currently logged in
- * @returns 422 when OTP is invalid
- * @returns 500 when OTP is malformed or for unknown errors
+ * @returns 422 on OTP creation or SMS send failure
+ * @returns 422 if user id does not exist in the database
+ * @returns 500 if database errors occurs
  */
-export const handleContactVerifyOtp: ControllerHandler<
+export const handleContactSendOtp = [
+  validateContactSendOtpParams,
+  _handleContactSendOtp,
+] as ControllerHandler[]
+
+export const _handleContactVerifyOtp: ControllerHandler<
   unknown,
   string | IPopulatedUser,
   {
@@ -158,6 +158,20 @@ export const handleContactVerifyOtp: ControllerHandler<
   return res.status(StatusCodes.OK).json(updateResult.value)
 }
 
+/**
+ * Verifies given OTP with the hashed OTP data, and updates the user's contact
+ * number if the hash matches.
+ * @route POST /contact/otp/verify
+ * @returns 200 when user contact update success
+ * @returns 401 if user id does not match current session user or if user is not currently logged in
+ * @returns 422 when OTP is invalid
+ * @returns 500 when OTP is malformed or for unknown errors
+ */
+export const handleContactVerifyOtp = [
+  validateContactOtpVerificationParams,
+  _handleContactVerifyOtp,
+] as ControllerHandler[]
+
 /**
  * Retrieves and returns the session user from the database.
  * @route GET /
diff --git a/src/app/modules/user/user.middleware.ts b/src/app/modules/user/user.middleware.ts
new file mode 100644
index 0000000000..4824d73b16
--- /dev/null
+++ b/src/app/modules/user/user.middleware.ts
@@ -0,0 +1,24 @@
+import { celebrate, Joi, Segments } from 'celebrate'
+
+/**
+ * Celebrate validation for the contact OTP sending endpoint.
+ */
+export const validateContactSendOtpParams = celebrate({
+  [Segments.BODY]: Joi.object().keys({
+    contact: Joi.string().required(),
+    userId: Joi.string().required(),
+  }),
+})
+
+/**
+ * Celebrate validation for the contact OTP verification endpoint.
+ */
+export const validateContactOtpVerificationParams = celebrate({
+  [Segments.BODY]: Joi.object({
+    userId: Joi.string().required(),
+    otp: Joi.string()
+      .required()
+      .regex(/^\d{6}$/),
+    contact: Joi.string().required(),
+  }),
+})
diff --git a/src/app/modules/user/user.routes.ts b/src/app/modules/user/user.routes.ts
index 7566344d1b..6dc5cb5188 100644
--- a/src/app/modules/user/user.routes.ts
+++ b/src/app/modules/user/user.routes.ts
@@ -1,4 +1,3 @@
-import { celebrate, Joi, Segments } from 'celebrate'
 import { Router } from 'express'
 
 import * as UserController from './user.controller'
@@ -28,16 +27,7 @@ UserRouter.get('/', UserController.handleFetchUser)
  * @returns 422 on OTP creation or SMS send failure, or if the user cannot be found
  * @returns 500 on application or database errors
  */
-UserRouter.post(
-  '/contact/sendotp',
-  celebrate({
-    [Segments.BODY]: Joi.object().keys({
-      contact: Joi.string().required(),
-      userId: Joi.string().required(),
-    }),
-  }),
-  UserController.handleContactSendOtp,
-)
+UserRouter.post('/contact/sendotp', UserController.handleContactSendOtp)
 
 /**
  * Verify the contact verification one-time password (OTP) for the user as part
@@ -50,18 +40,6 @@ UserRouter.post(
  * @returns 422 when OTP is invalid
  * @returns 500 when OTP is malformed or for unknown errors
  */
-UserRouter.post(
-  '/contact/verifyotp',
-  celebrate({
-    [Segments.BODY]: Joi.object().keys({
-      userId: Joi.string().required(),
-      otp: Joi.string()
-        .required()
-        .regex(/^\d{6}$/),
-      contact: Joi.string().required(),
-    }),
-  }),
-  UserController.handleContactVerifyOtp,
-)
+UserRouter.post('/contact/verifyotp', UserController.handleContactVerifyOtp)
 
 export default UserRouter
diff --git a/src/app/routes/api/v3/admin/forms/admin-forms.settings.routes.ts b/src/app/routes/api/v3/admin/forms/admin-forms.settings.routes.ts
index 40acc921a0..0bfcfbfab3 100644
--- a/src/app/routes/api/v3/admin/forms/admin-forms.settings.routes.ts
+++ b/src/app/routes/api/v3/admin/forms/admin-forms.settings.routes.ts
@@ -1,38 +1,9 @@
-import { celebrate, Joi, Segments } from 'celebrate'
 import { Router } from 'express'
 
-import {
-  FormAuthType,
-  FormStatus,
-  SettingsUpdateDto,
-} from '../../../../../../../shared/types'
 import * as AdminFormController from '../../../../../modules/form/admin-form/admin-form.controller'
 
 export const AdminFormsSettingsRouter = Router()
 
-/**
- * Joi validator for PATCH /forms/:formId/settings route.
- */
-const updateSettingsValidator = celebrate({
-  [Segments.BODY]: Joi.object<SettingsUpdateDto>({
-    authType: Joi.string().valid(...Object.values(FormAuthType)),
-    emails: Joi.alternatives().try(
-      Joi.array().items(Joi.string().email()),
-      Joi.string().email({ multiple: true }),
-    ),
-    esrvcId: Joi.string().allow(''),
-    hasCaptcha: Joi.boolean(),
-    inactiveMessage: Joi.string(),
-    status: Joi.string().valid(...Object.values(FormStatus)),
-    submissionLimit: Joi.number().allow(null),
-    title: Joi.string(),
-    webhook: Joi.object({
-      url: Joi.string().uri().allow(''),
-      isRetryEnabled: Joi.boolean(),
-    }).min(1),
-  }).min(1),
-})
-
 AdminFormsSettingsRouter.route('/:formId([a-fA-F0-9]{24})/settings')
   /**
    * Update form settings according to given subset of settings.
@@ -53,7 +24,7 @@ AdminFormsSettingsRouter.route('/:formId([a-fA-F0-9]{24})/settings')
    * @returns 422 when user in session cannot be retrieved from the database
    * @returns 500 when database error occurs
    */
-  .patch(updateSettingsValidator, AdminFormController.handleUpdateSettings)
+  .patch(AdminFormController.handleUpdateSettings)
   /**
    * Retrieve the settings of the specified form
    * @route GET /admin/forms/:formId/settings
diff --git a/src/app/routes/api/v3/auth/auth.routes.ts b/src/app/routes/api/v3/auth/auth.routes.ts
index 1bf1f9ecac..f34f29b2b7 100644
--- a/src/app/routes/api/v3/auth/auth.routes.ts
+++ b/src/app/routes/api/v3/auth/auth.routes.ts
@@ -1,4 +1,3 @@
-import { celebrate, Joi, Segments } from 'celebrate'
 import { Router } from 'express'
 
 import { rateLimitConfig } from '../../../../config/config'
@@ -14,19 +13,7 @@ export const AuthRouter = Router()
  * @return 200 when email domain is valid
  * @return 401 when email domain is invalid
  */
-AuthRouter.post(
-  '/email/validate',
-  celebrate({
-    [Segments.BODY]: Joi.object().keys({
-      email: Joi.string()
-        .required()
-        .email()
-        .message('Please enter a valid email')
-        .lowercase(),
-    }),
-  }),
-  AuthController.handleCheckUser,
-)
+AuthRouter.post('/email/validate', AuthController.handleCheckUser)
 
 /**
  * Send a one-time password (OTP) to the specified email address
@@ -43,15 +30,6 @@ AuthRouter.post(
 AuthRouter.post(
   '/otp/generate',
   limitRate({ max: rateLimitConfig.sendAuthOtp }),
-  celebrate({
-    [Segments.BODY]: Joi.object().keys({
-      email: Joi.string()
-        .required()
-        .email()
-        .message('Please enter a valid email')
-        .lowercase(),
-    }),
-  }),
   AuthController.handleLoginSendOtp,
 )
 
@@ -68,23 +46,7 @@ AuthRouter.post(
  * @returns 422 when the OTP is invalid
  * @returns 500 when error occurred whilst verifying the OTP
  */
-AuthRouter.post(
-  '/otp/verify',
-  celebrate({
-    [Segments.BODY]: Joi.object().keys({
-      email: Joi.string()
-        .required()
-        .email()
-        .message('Please enter a valid email')
-        .lowercase(),
-      otp: Joi.string()
-        .required()
-        .regex(/^\d{6}$/)
-        .message('Please enter a valid OTP'),
-    }),
-  }),
-  AuthController.handleLoginVerifyOtp,
-)
+AuthRouter.post('/otp/verify', AuthController.handleLoginVerifyOtp)
 
 /**
  * Sign the user out of the session by clearing the relevant session cookie
diff --git a/src/app/routes/api/v3/billings/billings.routes.ts b/src/app/routes/api/v3/billings/billings.routes.ts
index 91f3b2d5f2..6185a0d151 100644
--- a/src/app/routes/api/v3/billings/billings.routes.ts
+++ b/src/app/routes/api/v3/billings/billings.routes.ts
@@ -1,4 +1,3 @@
-import { celebrate, Joi, Segments } from 'celebrate'
 import { Router } from 'express'
 
 import { withUserAuthentication } from '../../../../modules/auth/auth.middlewares'
@@ -21,14 +20,4 @@ BillingsRouter.use(withUserAuthentication)
  * @return 401 when request does not contain a user session
  * @return 500 when error occurs whilst querying database
  */
-BillingsRouter.get(
-  '/',
-  celebrate({
-    [Segments.QUERY]: Joi.object({
-      esrvcId: Joi.string().required(),
-      yr: Joi.number().integer().min(2019).required(),
-      mth: Joi.number().integer().min(0).max(11).required(),
-    }),
-  }),
-  BillingController.handleGetBillInfo,
-)
+BillingsRouter.get('/', BillingController.handleGetBillInfo)
diff --git a/src/app/routes/api/v3/client/client.routes.ts b/src/app/routes/api/v3/client/client.routes.ts
index 521506d91a..6d0bf5830c 100644
--- a/src/app/routes/api/v3/client/client.routes.ts
+++ b/src/app/routes/api/v3/client/client.routes.ts
@@ -1,4 +1,3 @@
-import { celebrate, Joi, Segments } from 'celebrate'
 import { Router } from 'express'
 
 import * as FrontendServerController from '../../../../modules/frontend/frontend.controller'
@@ -40,14 +39,4 @@ ClientRouter.get('/features', FrontendServerController.showFeaturesStates)
  * @return 200 when redirect code is  successful
  * @return 400 when redirect code fails
  */
-ClientRouter.get(
-  '/redirect',
-  celebrate({
-    [Segments.QUERY]: {
-      redirectPath: Joi.string()
-        .regex(/^[a-fA-F0-9]{24}(\/(preview|template|use-template))?/)
-        .required(),
-    },
-  }),
-  FrontendServerController.generateRedirectUrl,
-)
+ClientRouter.get('/redirect', FrontendServerController.generateRedirectUrl)
diff --git a/src/app/routes/api/v3/user/user.routes.ts b/src/app/routes/api/v3/user/user.routes.ts
index d08165f93c..48c6392b57 100644
--- a/src/app/routes/api/v3/user/user.routes.ts
+++ b/src/app/routes/api/v3/user/user.routes.ts
@@ -1,4 +1,3 @@
-import { celebrate, Joi, Segments } from 'celebrate'
 import { Router } from 'express'
 
 import * as UserController from '../../../../modules/user/user.controller'
@@ -28,16 +27,7 @@ UserRouter.get('/', UserController.handleFetchUser)
  * @returns 422 on OTP creation or SMS send failure, or if the user cannot be found
  * @returns 500 on application or database errors
  */
-UserRouter.post(
-  '/contact/otp/generate',
-  celebrate({
-    [Segments.BODY]: Joi.object().keys({
-      contact: Joi.string().required(),
-      userId: Joi.string().required(),
-    }),
-  }),
-  UserController.handleContactSendOtp,
-)
+UserRouter.post('/contact/otp/generate', UserController.handleContactSendOtp)
 
 /**
  * Verify the contact verification one-time password (OTP) for the user as part
@@ -50,18 +40,6 @@ UserRouter.post(
  * @returns 422 when OTP is invalid
  * @returns 500 when OTP is malformed or for unknown errors
  */
-UserRouter.post(
-  '/contact/otp/verify',
-  celebrate({
-    [Segments.BODY]: Joi.object().keys({
-      userId: Joi.string().required(),
-      otp: Joi.string()
-        .required()
-        .regex(/^\d{6}$/),
-      contact: Joi.string().required(),
-    }),
-  }),
-  UserController.handleContactVerifyOtp,
-)
+UserRouter.post('/contact/otp/verify', UserController.handleContactVerifyOtp)
 
 export default UserRouter