diff --git a/src/main/java/com/mandacarubroker/controller/UserController.java b/src/main/java/com/mandacarubroker/controller/UserController.java
index 38d37461..fec1afb5 100644
--- a/src/main/java/com/mandacarubroker/controller/UserController.java
+++ b/src/main/java/com/mandacarubroker/controller/UserController.java
@@ -60,9 +60,6 @@ public ResponseEntity<ResponseUserDTO> getUserById(@PathVariable final String us
     })
     @PostMapping
     public ResponseEntity<ResponseUserDTO> createUser(@RequestBody @Valid final RequestUserDTO requestUserDTO) {
-        if (userService.verifyDuplicateUsername(requestUserDTO.username())) {
-            return ResponseEntity.status(HttpStatus.CONFLICT).build();
-        }
         ResponseUserDTO createdUser = userService.createUser(requestUserDTO);
         return ResponseEntity.status(HttpStatus.CREATED).body(createdUser);
     }
diff --git a/src/main/java/com/mandacarubroker/service/UserService.java b/src/main/java/com/mandacarubroker/service/UserService.java
index 7f2ceb36..fba87637 100644
--- a/src/main/java/com/mandacarubroker/service/UserService.java
+++ b/src/main/java/com/mandacarubroker/service/UserService.java
@@ -4,10 +4,11 @@
 import com.mandacarubroker.domain.user.ResponseUserDTO;
 import com.mandacarubroker.domain.user.User;
 import com.mandacarubroker.domain.user.UserRepository;
+import org.springframework.http.HttpStatus;
 import org.springframework.security.core.userdetails.UserDetails;
 import org.springframework.security.core.userdetails.UserDetailsService;
-import org.springframework.security.core.userdetails.UsernameNotFoundException;
 import org.springframework.stereotype.Service;
+import org.springframework.web.server.ResponseStatusException;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -62,6 +63,9 @@ private User hashPassword(final User user) {
     }
 
     public ResponseUserDTO createUser(final RequestUserDTO requestUserDTO) {
+        if (verifyDuplicateUsername(requestUserDTO.username())) {
+            throw new ResponseStatusException(HttpStatus.CONFLICT, "this username is not available");
+        }
         validateRequestDTO(requestUserDTO);
         User newUser = new User(requestUserDTO);
         User hashedPasswordUser = hashPassword(newUser);
@@ -94,13 +98,13 @@ public void deleteUser(final String id) {
 
     public UserDetails loadUserByUsername(final String username) {
         if (username == null || username.isEmpty()) {
-            throw new UsernameNotFoundException("Username is required");
+            throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Username cannot be null or empty");
         }
 
         User user = userRepository.findByUsername(username);
 
         if (user == null) {
-            throw new UsernameNotFoundException("User not found");
+            throw new ResponseStatusException(HttpStatus.NOT_FOUND, "User not found");
         }
 
         return user;
diff --git a/src/test/java/com/mandacarubroker/controller/UserControllerIT.java b/src/test/java/com/mandacarubroker/controller/UserControllerIT.java
index 792e02b5..5c4abc6a 100644
--- a/src/test/java/com/mandacarubroker/controller/UserControllerIT.java
+++ b/src/test/java/com/mandacarubroker/controller/UserControllerIT.java
@@ -203,6 +203,7 @@ void itShouldReturnCreatedStatusAfterSucessfulPost() throws Exception {
                 mockMvc.perform(requestBuilder).andExpect(matchStatus);
         }
 
+        @Test
         void itShouldReturnUserDataAfterSucessfulPost() throws Exception {
                 String userJsonString = objectMapper.writeValueAsString(validUserDTO);
                 System.out.println(userJsonString);
@@ -217,6 +218,7 @@ void itShouldReturnUserDataAfterSucessfulPost() throws Exception {
                 assertResponseUserDTO(validUserDTO, createdUser);
         }
 
+        @Test
         void itShouldReturnUserDataAfterSucessfulPut() throws Exception {
                 String userJsonString = objectMapper.writeValueAsString(validUserDTO);