diff --git a/lib/validations/shared/queryUserId.ts b/lib/validations/shared/queryUserId.ts
new file mode 100644
index 0000000000..cbe6e282d2
--- /dev/null
+++ b/lib/validations/shared/queryUserId.ts
@@ -0,0 +1,15 @@
+import { withValidation } from "next-validations";
+import { z } from "zod";
+
+import { baseApiParams } from "./baseApiParams";
+
+// Extracted out as utility function so can be reused
+// at different endpoints that require this validation.
+export const schemaQueryUserId = baseApiParams
+  .extend({
+    userId: z
+      .string()
+      .regex(/^\d+$/)
+      .transform((id) => parseInt(id)),
+  })
+  .strict();
diff --git a/pages/api/availability/_get.ts b/pages/api/availability/_get.ts
index 21450f005e..5289190c03 100644
--- a/pages/api/availability/_get.ts
+++ b/pages/api/availability/_get.ts
@@ -7,7 +7,7 @@ import { stringOrNumber } from "@calcom/prisma/zod-utils";
 
 const availabilitySchema = z
   .object({
-    userId: stringOrNumber.optional(),
+    userId: stringOrNumber,
     username: z.string().optional(),
     dateFrom: z.string(),
     dateTo: z.string(),
diff --git a/pages/api/users/[id]/_delete.ts b/pages/api/users/[userId]/_delete.ts
similarity index 84%
rename from pages/api/users/[id]/_delete.ts
rename to pages/api/users/[userId]/_delete.ts
index 7d38d07372..3478c44789 100644
--- a/pages/api/users/[id]/_delete.ts
+++ b/pages/api/users/[userId]/_delete.ts
@@ -5,7 +5,7 @@ import { defaultResponder } from "@calcom/lib/server";
 import prisma from "@calcom/prisma";
 
 import { isAdminGuard } from "@lib/utils/isAdmin";
-import { schemaQueryIdParseInt } from "@lib/validations/shared/queryIdTransformParseInt";
+import { schemaQueryUserId } from "@lib/validations/shared/queryUserId";
 
 /**
  * @swagger
@@ -32,10 +32,11 @@ import { schemaQueryIdParseInt } from "@lib/validations/shared/queryIdTransformP
  *        description: Authorization information is missing or invalid.
  */
 export async function deleteHandler(req: NextApiRequest) {
-  const query = schemaQueryIdParseInt.parse(req.query);
+  const query = schemaQueryUserId.parse(req.query);
   const isAdmin = await isAdminGuard(req.userId);
   // Here we only check for ownership of the user if the user is not admin, otherwise we let ADMIN's edit any user
-  if (!isAdmin && query.id !== req.userId) throw new HttpError({ statusCode: 401, message: "Unauthorized" });
+  if (!isAdmin && query.userId !== req.userId)
+    throw new HttpError({ statusCode: 401, message: "Unauthorized" });
 
   const user = await prisma.user.findUnique({ where: { id: query.id } });
   if (!user) throw new HttpError({ statusCode: 404, message: "User not found" });
diff --git a/pages/api/users/[id]/_get.ts b/pages/api/users/[userId]/_get.ts
similarity index 82%
rename from pages/api/users/[id]/_get.ts
rename to pages/api/users/[userId]/_get.ts
index 443b935e9c..5c76c4e315 100644
--- a/pages/api/users/[id]/_get.ts
+++ b/pages/api/users/[userId]/_get.ts
@@ -5,7 +5,7 @@ import { defaultResponder } from "@calcom/lib/server";
 import prisma from "@calcom/prisma";
 
 import { isAdminGuard } from "@lib/utils/isAdmin";
-import { schemaQueryIdParseInt } from "@lib/validations/shared/queryIdTransformParseInt";
+import { schemaQueryUserId } from "@lib/validations/shared/queryUserId";
 import { schemaUserReadPublic } from "@lib/validations/user";
 
 /**
@@ -33,11 +33,12 @@ import { schemaUserReadPublic } from "@lib/validations/user";
  *         description: User was not found
  */
 export async function getHandler(req: NextApiRequest) {
-  const query = schemaQueryIdParseInt.parse(req.query);
+  const query = schemaQueryUserId.parse(req.query);
   const isAdmin = await isAdminGuard(req.userId);
   // Here we only check for ownership of the user if the user is not admin, otherwise we let ADMIN's edit any user
-  if (!isAdmin && query.id !== req.userId) throw new HttpError({ statusCode: 401, message: "Unauthorized" });
-  const data = await prisma.user.findUnique({ where: { id: query.id } });
+  if (!isAdmin && query.userId !== req.userId)
+    throw new HttpError({ statusCode: 401, message: "Unauthorized" });
+  const data = await prisma.user.findUnique({ where: { id: query.userId } });
   const user = schemaUserReadPublic.parse(data);
   return { user };
 }
diff --git a/pages/api/users/[id]/_patch.ts b/pages/api/users/[userId]/_patch.ts
similarity index 90%
rename from pages/api/users/[id]/_patch.ts
rename to pages/api/users/[userId]/_patch.ts
index a6551609e7..9f32e920c4 100644
--- a/pages/api/users/[id]/_patch.ts
+++ b/pages/api/users/[userId]/_patch.ts
@@ -5,7 +5,7 @@ import { defaultResponder } from "@calcom/lib/server";
 import prisma from "@calcom/prisma";
 
 import { isAdminGuard } from "@lib/utils/isAdmin";
-import { schemaQueryIdParseInt } from "@lib/validations/shared/queryIdTransformParseInt";
+import { schemaQueryUserId } from "@lib/validations/shared/queryUserId";
 import { schemaUserEditBodyParams, schemaUserReadPublic } from "@lib/validations/user";
 
 /**
@@ -54,10 +54,11 @@ import { schemaUserEditBodyParams, schemaUserReadPublic } from "@lib/validations
  *        description: Authorization information is missing or invalid.
  */
 export async function patchHandler(req: NextApiRequest) {
-  const query = schemaQueryIdParseInt.parse(req.query);
+  const query = schemaQueryUserId.parse(req.query);
   const isAdmin = await isAdminGuard(req.userId);
   // Here we only check for ownership of the user if the user is not admin, otherwise we let ADMIN's edit any user
-  if (!isAdmin && query.id !== req.userId) throw new HttpError({ statusCode: 401, message: "Unauthorized" });
+  if (!isAdmin && query.userId !== req.userId)
+    throw new HttpError({ statusCode: 401, message: "Unauthorized" });
 
   const body = schemaUserEditBodyParams.parse(req.body);
   const userSchedules = await prisma.schedule.findMany({
diff --git a/pages/api/users/[userId]/availability/index.ts b/pages/api/users/[userId]/availability/index.ts
new file mode 100644
index 0000000000..1a27360f81
--- /dev/null
+++ b/pages/api/users/[userId]/availability/index.ts
@@ -0,0 +1,9 @@
+import { defaultHandler } from "@calcom/lib/server";
+
+import { withMiddleware } from "@lib/helpers/withMiddleware";
+
+export default withMiddleware("HTTP_GET")(
+  defaultHandler({
+    GET: import("@api/availability/_get"),
+  })
+);
diff --git a/pages/api/users/[id]/index.ts b/pages/api/users/[userId]/index.ts
similarity index 100%
rename from pages/api/users/[id]/index.ts
rename to pages/api/users/[userId]/index.ts