diff --git a/backend/src/ee/routes/v1/pki-acme-router.ts b/backend/src/ee/routes/v1/pki-acme-router.ts
index e576eb306..362c8b38e 100644
--- a/backend/src/ee/routes/v1/pki-acme-router.ts
+++ b/backend/src/ee/routes/v1/pki-acme-router.ts
@@ -10,15 +10,18 @@ import {
   DeactivateAcmeAccountBodySchema,
   DeactivateAcmeAccountResponseSchema,
   FinalizeAcmeOrderBodySchema,
+  FinalizeAcmeOrderResponseSchema,
   GetAcmeAuthorizationResponseSchema,
   GetAcmeDirectoryResponseSchema,
   GetAcmeOrderResponseSchema,
+  ListAcmeOrdersPayloadSchema,
   ListAcmeOrdersResponseSchema,
   RawJwsPayloadSchema,
   RespondToAcmeChallengeResponseSchema
 } from "@app/ee/services/pki-acme/pki-acme-schemas";
 import { ApiDocsTags } from "@app/lib/api-docs";
 import { readLimit, writeLimit } from "@app/server/config/rateLimiter";
+import { AcmeAccountDoesNotExistError, AcmeMalformedError } from "@app/ee/services/pki-acme/pki-acme-errors";
 
 export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
   const sendAcmeResponse = async <T>(res: FastifyReply, profileId: string, response: TAcmeResponse<T>): Promise<T> => {
@@ -158,16 +161,16 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
     // TODO: replace with verify ACME signature here instead
     // onRequest: verifyAuth([AuthMode.JWT, AuthMode.IDENTITY_ACCESS_TOKEN]),
     handler: async (req, res) => {
-      const { payload, accountId } = await server.services.pkiAcme.validateExistingAccountJwsPayload(
-        req.params.profileId,
-        req.body,
-        CreateAcmeOrderBodySchema
-      );
+      const { profileId, accountId, payload } = await server.services.pkiAcme.validateExistingAccountJwsPayload({
+        profileId: req.params.profileId,
+        rawJwsPayload: req.body,
+        schema: CreateAcmeOrderBodySchema
+      });
       return sendAcmeResponse(
         res,
-        req.params.profileId,
+        profileId,
         await server.services.pkiAcme.createAcmeOrder({
-          profileId: req.params.profileId,
+          profileId,
           accountId,
           payload
         })
@@ -191,7 +194,7 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
         profileId: z.string().uuid(),
         accountId: z.string()
       }),
-      body: DeactivateAcmeAccountBodySchema,
+      body: RawJwsPayloadSchema,
       response: {
         200: DeactivateAcmeAccountResponseSchema
       }
@@ -199,13 +202,19 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
     // TODO: replace with verify ACME signature here instead
     // onRequest: verifyAuth([AuthMode.JWT, AuthMode.IDENTITY_ACCESS_TOKEN]),
     handler: async (req, res) => {
+      const { payload, profileId, accountId } = await server.services.pkiAcme.validateExistingAccountJwsPayload({
+        profileId: req.params.profileId,
+        rawJwsPayload: req.body,
+        schema: DeactivateAcmeAccountBodySchema,
+        expectedAccountId: req.params.accountId
+      });
       return sendAcmeResponse(
         res,
-        req.params.profileId,
+        profileId,
         await server.services.pkiAcme.deactivateAcmeAccount({
-          profileId: req.params.profileId,
-          accountId: req.params.accountId,
-          payload: req.body
+          profileId,
+          accountId,
+          payload
         })
       );
     }
@@ -227,15 +236,28 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
         profileId: z.string().uuid(),
         accountId: z.string()
       }),
+      body: RawJwsPayloadSchema,
       response: {
         200: ListAcmeOrdersResponseSchema
       }
     },
     // TODO: replace with verify ACME signature here instead
     // onRequest: verifyAuth([AuthMode.JWT, AuthMode.IDENTITY_ACCESS_TOKEN]),
-    handler: async (req) => {
-      const orders = await server.services.pkiAcme.listAcmeOrders(req.params.profileId, req.params.accountId);
-      return orders;
+    handler: async (req, res) => {
+      const { profileId, accountId } = await server.services.pkiAcme.validateExistingAccountJwsPayload({
+        profileId: req.params.profileId,
+        rawJwsPayload: req.body,
+        schema: ListAcmeOrdersPayloadSchema,
+        expectedAccountId: req.params.accountId
+      });
+      return sendAcmeResponse(
+        res,
+        profileId,
+        await server.services.pkiAcme.listAcmeOrders({
+          profileId,
+          accountId
+        })
+      );
     }
   });
 
@@ -255,15 +277,27 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
         profileId: z.string().uuid(),
         orderId: z.string().uuid()
       }),
+      body: RawJwsPayloadSchema,
       response: {
         200: GetAcmeOrderResponseSchema
       }
     },
     // TODO: replace with verify ACME signature here instead
     // onRequest: verifyAuth([AuthMode.JWT, AuthMode.IDENTITY_ACCESS_TOKEN]),
-    handler: async (req) => {
-      const order = await server.services.pkiAcme.getAcmeOrder(req.params.profileId, req.params.orderId);
-      return order;
+    handler: async (req, res) => {
+      const { profileId, accountId } = await server.services.pkiAcme.validateExistingAccountJwsPayload({
+        profileId: req.params.profileId,
+        rawJwsPayload: req.body
+      });
+      return sendAcmeResponse(
+        res,
+        profileId,
+        await server.services.pkiAcme.getAcmeOrder({
+          profileId,
+          accountId,
+          orderId: req.params.orderId
+        })
+      );
     }
   });
 
@@ -283,13 +317,29 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
         profileId: z.string().uuid(),
         orderId: z.string().uuid()
       }),
-      body: FinalizeAcmeOrderBodySchema
+      body: RawJwsPayloadSchema,
+      response: {
+        200: FinalizeAcmeOrderResponseSchema
+      }
     },
     // TODO: replace with verify ACME signature here instead
     // onRequest: verifyAuth([AuthMode.JWT, AuthMode.IDENTITY_ACCESS_TOKEN]),
-    handler: async (req) => {
-      const order = await server.services.pkiAcme.finalizeAcmeOrder(req.params.profileId, req.params.orderId, req.body);
-      return order;
+    handler: async (req, res) => {
+      const {  profileId, accountId, payload } = await server.services.pkiAcme.validateExistingAccountJwsPayload({
+        profileId: req.params.profileId,
+        rawJwsPayload: req.body
+        schema: FinalizeAcmeOrderBodySchema,
+      });
+      return sendAcmeResponse(
+        res,
+        profileId,
+        await server.services.pkiAcme.finalizeAcmeOrder({
+          profileId,
+          accountId,
+          orderId: req.params.orderId,
+          payload
+        })
+      );
     }
   });
 
@@ -309,6 +359,7 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
         profileId: z.string().uuid(),
         orderId: z.string().uuid()
       }),
+      body: RawJwsPayloadSchema,
       response: {
         200: z.string()
       }
@@ -316,12 +367,19 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
     // TODO: replace with verify ACME signature here instead
     // onRequest: verifyAuth([AuthMode.JWT, AuthMode.IDENTITY_ACCESS_TOKEN]),
     handler: async (req, res) => {
-      const certificate = await server.services.pkiAcme.downloadAcmeCertificate(
-        req.params.profileId,
-        req.params.orderId
+      const { profileId, accountId } = await server.services.pkiAcme.validateExistingAccountJwsPayload({
+        profileId: req.params.profileId,
+        rawJwsPayload: req.body
+      });
+      return sendAcmeResponse(
+        res,
+        profileId,
+        await server.services.pkiAcme.downloadAcmeCertificate({
+          profileId,
+          accountId,
+          orderId: req.params.orderId
+        })
       );
-      res.header("Content-Type", "application/pem-certificate-chain");
-      return certificate;
     }
   });
 
@@ -341,15 +399,30 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
         profileId: z.string().uuid(),
         authzId: z.string().uuid()
       }),
+      body: RawJwsPayloadSchema,
       response: {
         200: GetAcmeAuthorizationResponseSchema
       }
     },
     // TODO: replace with verify ACME signature here instead
     // onRequest: verifyAuth([AuthMode.JWT, AuthMode.IDENTITY_ACCESS_TOKEN]),
-    handler: async (req) => {
-      const authz = await server.services.pkiAcme.getAcmeAuthorization(req.params.profileId, req.params.authzId);
-      return authz;
+    handler: async (req, res) => {
+      const { profileId, accountId, payload } = await server.services.pkiAcme.validateExistingAccountJwsPayload({
+        profileId: req.params.profileId,
+        rawJwsPayload: req.body
+      });
+      if (payload !== "") {
+        throw new AcmeMalformedError({ detail: "Payload should be empty" });
+      }
+      return sendAcmeResponse(
+        res,
+        profileId,
+        await server.services.pkiAcme.getAcmeAuthorization({
+          profileId,
+          accountId,
+          authzId: req.params.authzId
+        })
+      );
     }
   });
 
diff --git a/backend/src/ee/services/pki-acme/pki-acme-service.ts b/backend/src/ee/services/pki-acme/pki-acme-service.ts
index 9b6f9d4e5..4d51e31dd 100644
--- a/backend/src/ee/services/pki-acme/pki-acme-service.ts
+++ b/backend/src/ee/services/pki-acme/pki-acme-service.ts
@@ -93,10 +93,13 @@ export const pkiAcmeServiceFactory = ({
     return kid.slice(kidPrefix.length);
   };
 
-  const validateJwsPayload = async <T>(
+  const validateJwsPayload = async <
+    TSchema extends z.ZodSchema<any> | undefined = undefined,
+    T = TSchema extends z.ZodSchema<infer R> ? R : string
+  >(
     rawJwsPayload: TRawJwsPayload,
     getJWK: (protectedHeader: JWSHeaderParameters) => Promise<JsonWebKey>,
-    schema: z.ZodSchema<T>
+    schema?: TSchema
   ): Promise<TJwsPayload<T>> => {
     let result: FlattenedVerifyResult;
     try {
@@ -122,8 +125,8 @@ export const pkiAcmeServiceFactory = ({
       const protectedHeader = ProtectedHeaderSchema.parse(rawProtectedHeader);
       // TODO: consume the nonce here
       const decoder = new TextDecoder();
-      const jsonPayload = JSON.parse(decoder.decode(rawPayload));
-      const payload = schema.parse(jsonPayload);
+      const textPayload = decoder.decode(rawPayload);
+      const payload = schema ? schema.parse(JSON.parse(textPayload)) : textPayload;
       return {
         protectedHeader,
         payload
@@ -152,7 +155,10 @@ export const pkiAcmeServiceFactory = ({
     );
   };
 
-  const validateExistingAccountJwsPayload = async <T>({
+  const validateExistingAccountJwsPayload = async <
+    TSchema extends z.ZodSchema<any> | undefined = undefined,
+    T = TSchema extends z.ZodSchema<infer R> ? R : string
+  >({
     profileId,
     rawJwsPayload,
     schema,
@@ -160,7 +166,7 @@ export const pkiAcmeServiceFactory = ({
   }: {
     profileId: string;
     rawJwsPayload: TRawJwsPayload;
-    schema: z.ZodSchema<T>;
+    schema?: TSchema;
     expectedAccountId?: string;
   }): Promise<TAuthenciatedJwsPayload<T>> => {
     const profile = await validateAcmeProfile(profileId);
@@ -187,7 +193,8 @@ export const pkiAcmeServiceFactory = ({
     );
     return {
       ...result,
-      accountId: extractAccountIdFromKid(result.protectedHeader.kid!, profileId)
+      accountId: extractAccountIdFromKid(result.protectedHeader.kid!, profileId),
+      profileId
     };
   };
 
@@ -406,10 +413,12 @@ export const pkiAcmeServiceFactory = ({
 
   const finalizeAcmeOrder = async ({
     profileId,
+    accountId,
     orderId,
     payload
   }: {
     profileId: string;
+    accountId: string;
     orderId: string;
     payload: TFinalizeAcmeOrderPayload;
   }): Promise<TAcmeResponse<TFinalizeAcmeOrderResponse>> => {
@@ -453,12 +462,18 @@ export const pkiAcmeServiceFactory = ({
 
   const getAcmeAuthorization = async ({
     profileId,
+    accountId,
     authzId
   }: {
     profileId: string;
+    accountId: string;
     authzId: string;
   }): Promise<TAcmeResponse<TGetAcmeAuthorizationResponse>> => {
     const profile = await validateAcmeProfile(profileId);
+    const order = await acmeOrderDAL.findByIdWithAuthorizations(orderId);
+    if (!order || order.accountId !== accountId) {
+      throw new NotFoundError({ message: "ACME order not found" });
+    }
     // FIXME: Implement ACME authorization retrieval
     return {
       status: 200,
diff --git a/backend/src/ee/services/pki-acme/pki-acme-types.ts b/backend/src/ee/services/pki-acme/pki-acme-types.ts
index e9fa4ffa0..a1f65d8f8 100644
--- a/backend/src/ee/services/pki-acme/pki-acme-types.ts
+++ b/backend/src/ee/services/pki-acme/pki-acme-types.ts
@@ -43,6 +43,7 @@ export type TJwsPayload<T> = {
   payload: T;
 };
 export type TAuthenciatedJwsPayload<T> = TJwsPayload<T> & {
+  profileId: string;
   accountId: string;
 };
 export type TAcmeResponse<TPayload> = {
@@ -52,13 +53,19 @@ export type TAcmeResponse<TPayload> = {
 };
 
 export type TPkiAcmeServiceFactory = {
-  validateJwsPayload: <T>(
+  validateJwsPayload: <
+    TSchema extends z.ZodSchema<any> | undefined = undefined,
+    T = TSchema extends z.ZodSchema<infer R> ? R : string
+  >(
     rawJwsPayload: TRawJwsPayload,
     getJWK: (protectedHeader: JWSHeaderParameters) => Promise<JsonWebKey>,
-    schema: z.ZodSchema<T>
+    schema?: TSchema
   ) => Promise<TJwsPayload<T>>;
   validateNewAccountJwsPayload: (rawJwsPayload: TRawJwsPayload) => Promise<TJwsPayload<TCreateAcmeAccountPayload>>;
-  validateExistingAccountJwsPayload: <T>({
+  validateExistingAccountJwsPayload: <
+    TSchema extends z.ZodSchema<any> | undefined = undefined,
+    T = TSchema extends z.ZodSchema<infer R> ? R : string
+  >({
     profileId,
     rawJwsPayload,
     schema,
@@ -66,7 +73,7 @@ export type TPkiAcmeServiceFactory = {
   }: {
     profileId: string;
     rawJwsPayload: TRawJwsPayload;
-    schema: z.ZodSchema<T>;
+    schema?: TSchema;
     expectedAccountId?: string;
   }) => Promise<TAuthenciatedJwsPayload<T>>;
   getAcmeDirectory: (profileId: string) => Promise<TGetAcmeDirectoryResponse>;
@@ -118,10 +125,12 @@ export type TPkiAcmeServiceFactory = {
   }) => Promise<TAcmeResponse<TGetAcmeOrderResponse>>;
   finalizeAcmeOrder: ({
     profileId,
+    accountId,
     orderId,
     payload
   }: {
     profileId: string;
+    accountId: string;
     orderId: string;
     payload: TFinalizeAcmeOrderPayload;
   }) => Promise<TAcmeResponse<TFinalizeAcmeOrderResponse>>;