diff --git a/users/userservice/src/controllers/user-controller.ts b/users/userservice/src/controllers/user-controller.ts
index c1dd8eb1..df8d7cdd 100644
--- a/users/userservice/src/controllers/user-controller.ts
+++ b/users/userservice/src/controllers/user-controller.ts
@@ -1,6 +1,7 @@
 import { Request, Response } from 'express';
 import bcrypt from 'bcrypt';
 import { validateProfileBody } from '../utils/profile-body-validation';
+import { validateNoSpaces, validateMaxLength } from '../utils/username-validation';
 
 const {
   validateRequiredFields,
@@ -17,6 +18,8 @@ const addUser = async (req: Request, res: Response) => {
     validateRequiredFields(req, ['username', 'password']);
     validateNotEmpty(req, ['username']);
     validateRequiredLength(req, ['password'], 8);
+    validateNoSpaces(req, ['username']);
+    validateMaxLength(req, ['username'], 20);
 
     const username = req.body.username.toString();
     const password = req.body.password.toString();
diff --git a/users/userservice/src/utils/username-validation.ts b/users/userservice/src/utils/username-validation.ts
new file mode 100644
index 00000000..fadfe530
--- /dev/null
+++ b/users/userservice/src/utils/username-validation.ts
@@ -0,0 +1,19 @@
+import { Request } from 'express';
+
+function validateNoSpaces(req: Request, fieldsThatCannotHaveSpace: string[]) {
+    for (const field of fieldsThatCannotHaveSpace) {
+        if (req.body[field]!.indexOf(' ') >= 0) {
+            throw new Error(`The field "${field}" cannot have spaces`);
+        }
+    }
+}
+
+function validateMaxLength(req: Request, fields: string[], maxLength: number) {
+    for (const field of fields) {
+        if (req.body[field]!.length > maxLength) {
+            throw new Error(`The field "${field}" cannot have more than ${maxLength} characters`);
+        }
+    }
+}
+
+export { validateNoSpaces, validateMaxLength };
\ No newline at end of file
diff --git a/users/userservice/test/user-service.test.ts b/users/userservice/test/user-service.test.ts
index 8fe74efd..f86dc1e3 100644
--- a/users/userservice/test/user-service.test.ts
+++ b/users/userservice/test/user-service.test.ts
@@ -47,6 +47,26 @@ describe('User Service', () => {
     expect(response.status).toBe(400);
   });
 
+  it('should get an error when registering a user with a blank space on POST /adduser', async () => {
+    const newUser = {
+      username: 'invaliduser01 ',
+      password: 'testpassword2',
+    };
+
+    const response = await request(app).post('/adduser').send(newUser);
+    expect(response.status).toBe(400);
+  });
+
+  it('should get an error when registering a user with more than 20 characters POST /adduser', async () => {
+    const newUser = {
+      username: 'thisusernamehasmorethan20characters',
+      password: 'testpassword2',
+    };
+
+    const response = await request(app).post('/adduser').send(newUser);
+    expect(response.status).toBe(400);
+  });
+
   // GET /history error (no user)
   it('should get an error in GET /history when not passing a user', async () => {
     const response = await request(app)