diff --git a/__test__/user.test.ts b/__test__/user.test.ts
index 739538e..32e9a70 100644
--- a/__test__/user.test.ts
+++ b/__test__/user.test.ts
@@ -44,14 +44,14 @@ test('should return 409 when registering with an existing email', async () => {
   .send(userData); 
   expect(response.status).toBe(409); }, 20000); 
 
-test('should return 500 when registering with an invalid credential', async () => { 
+test('should return 400 when registering with an invalid credential', async () => { 
   const userData = { 
   email: 'test@mail.com', name: "", username: 'existinguser', }; 
   const response = await request(app) 
   .post('/api/v1/users/register')
    .send(userData); 
    
-   expect(response.status).toBe(500); }, 20000); });
+   expect(response.status).toBe(400); }, 20000); });
 
   test("should return all users in db --> given '/api/v1/users'", async () => {
     const spy = jest.spyOn(User, "findAll");
diff --git a/package.json b/package.json
index e8bd346..e693874 100644
--- a/package.json
+++ b/package.json
@@ -52,7 +52,9 @@
     "cross-env": "^7.0.3",
     "cryptr": "^6.3.0",
     "dotenv": "^16.4.5",
+    "email-validator": "^2.0.4",
     "express": "^4.19.2",
+    "joi": "^17.12.3",
     "jsonwebtoken": "^9.0.2",
     "path": "^0.12.7",
     "pg": "^8.11.5",
diff --git a/src/controllers/userControllers.ts b/src/controllers/userControllers.ts
index bf37e46..f3fed45 100644
--- a/src/controllers/userControllers.ts
+++ b/src/controllers/userControllers.ts
@@ -56,14 +56,17 @@ export const userLogin =  async(req:Request,res:Response) =>{
 
 
 export const createUserController = async (req: Request, res: Response) => {
-  try {
+  try {  
     const { name, email, username, password } = req.body;
     const user = await createUserService(name, email, username, password);
+    
     if (!user) {
       return res.status(409).json({ 
         status: 409, 
-        message: 'User already exists' });
+        message: 'Username or email already exists' 
+      });
     }
+    
     res.status(201).json({ 
       status: 201, 
       message: "User successfully created." 
diff --git a/src/middleware/validator.ts b/src/middleware/validator.ts
new file mode 100644
index 0000000..93cc2b8
--- /dev/null
+++ b/src/middleware/validator.ts
@@ -0,0 +1,35 @@
+import { Request, Response, NextFunction } from 'express';
+import validator from 'email-validator';
+import { Schema } from 'joi';
+
+export const emailValidation = (req: Request, res: Response, next: NextFunction) => {
+  const { email } = req.body;
+
+  if (!email) {
+    return res.status(400).json({
+      status: 400,
+      message: "Email is required"
+    });
+  }
+
+  const isValid = validator.validate(email);
+  if (isValid) {
+    next(); 
+  } else {
+    return res.status(400).json({
+      status: 400,
+      message: "Email is not valid."
+    });
+  }
+};
+
+
+export const validateSchema = (schema: Schema) => {
+  return (req: Request, res: Response, next: NextFunction) => {
+      const { error } = schema.validate(req.body);
+      if (error) {
+          return res.status(400).json({ message: error.details[0].message });
+      }
+      next();
+  };
+};
\ No newline at end of file
diff --git a/src/routes/userRoutes.ts b/src/routes/userRoutes.ts
index 3b60d5d..23d9f47 100644
--- a/src/routes/userRoutes.ts
+++ b/src/routes/userRoutes.ts
@@ -4,12 +4,21 @@ import {
     createUserController,
     userLogin  } 
 from "../controllers/userControllers";
+import { 
+    emailValidation,
+    validateSchema,
+ } from "../middleware/validator";
+import signUpSchema from "../schemas/signUpSchema";
 
 const userRoutes = Router();
 
 userRoutes.get("/", fetchAllUsers);
 userRoutes.post('/login',userLogin);
-userRoutes.post("/register", createUserController)
+userRoutes.post("/register", 
+ emailValidation, 
+ validateSchema(signUpSchema), 
+ createUserController
+)
 
 
-export default userRoutes;
+export default userRoutes;  
diff --git a/src/schemas/signUpSchema.ts b/src/schemas/signUpSchema.ts
new file mode 100644
index 0000000..030fcd3
--- /dev/null
+++ b/src/schemas/signUpSchema.ts
@@ -0,0 +1,21 @@
+import Joi from "joi";
+
+export const signUpSchema = Joi.object({
+    name: Joi.string()
+        .min(5)
+        .max(40)
+        .required(),
+    username: Joi.string()
+        .min(4)
+        .required(),
+    email: Joi.string()
+        .min(6)
+        .required()
+        .email(),
+    password: Joi.string()
+        .min(6)
+        .max(20)
+        .required()
+}).options({ allowUnknown: false });
+
+export default signUpSchema
\ No newline at end of file
diff --git a/src/services/user.service.ts b/src/services/user.service.ts
index 0f12e3d..dbdeae8 100644
--- a/src/services/user.service.ts
+++ b/src/services/user.service.ts
@@ -1,6 +1,7 @@
 import { errors } from "undici-types";
 import User from "../sequelize/models/users";
-import { hashedPassword } from "../helpers/hashPassword";
+import { hashedPassword } from "../utils/hashPassword";
+import { Op } from "sequelize";
 
 export const getAllUsers = async () => {
   try {
@@ -30,7 +31,11 @@ export const loggedInUser = async(email:string) => {
 };
 };
 export const createUserService = async (name: string, email: string, username: string, password: string): Promise<User | null> => {
-  const existingUser = await User.findOne({ where: { email } });
+  const existingUser = await User.findOne({ 
+    where: { 
+      [Op.or]: [{ email }, { username }] 
+    } 
+  });
   if (existingUser) {
     return null; 
   }
diff --git a/src/helpers/hashPassword.ts b/src/utils/hashPassword.ts
similarity index 100%
rename from src/helpers/hashPassword.ts
rename to src/utils/hashPassword.ts