diff --git a/backend/src/main/java/share/fare/backend/exception/FareShareResponseEntityExceptionHandler.java b/backend/src/main/java/share/fare/backend/exception/FareShareResponseEntityExceptionHandler.java
index 90273b3..895195b 100644
--- a/backend/src/main/java/share/fare/backend/exception/FareShareResponseEntityExceptionHandler.java
+++ b/backend/src/main/java/share/fare/backend/exception/FareShareResponseEntityExceptionHandler.java
@@ -69,7 +69,7 @@ public final ResponseEntity<ErrorDetails> userAlreadyInGroupException(Exception
     @ExceptionHandler(UserIsNotInGroupException.class)
     public final ResponseEntity<ErrorDetails> userIsNotInGroupException(Exception ex, WebRequest request) {
         ErrorDetails errorDetails = new ErrorDetails(LocalDateTime.now(), ex.getMessage(), request.getDescription(false), ex.getStackTrace().length);
-        return new ResponseEntity<>(errorDetails, HttpStatus.CONFLICT);
+        return new ResponseEntity<>(errorDetails, HttpStatus.FORBIDDEN);
     }
 
     @ExceptionHandler(UserIsNotGroupOwner.class)
diff --git a/backend/src/main/java/share/fare/backend/exception/UserIsNotInGroupException.java b/backend/src/main/java/share/fare/backend/exception/UserIsNotInGroupException.java
index 119fc05..012bd47 100644
--- a/backend/src/main/java/share/fare/backend/exception/UserIsNotInGroupException.java
+++ b/backend/src/main/java/share/fare/backend/exception/UserIsNotInGroupException.java
@@ -4,7 +4,7 @@
 import org.springframework.http.HttpStatus;
 import org.springframework.web.bind.annotation.ResponseStatus;
 
-@ResponseStatus(HttpStatus.CONFLICT)
+@ResponseStatus(HttpStatus.FORBIDDEN)
 public class UserIsNotInGroupException extends RuntimeException {
     public UserIsNotInGroupException(String message) {
         super(message);
diff --git a/backend/src/test/java/share/fare/backend/controller/GroupChatControllerTest.java b/backend/src/test/java/share/fare/backend/controller/GroupChatControllerTest.java
index ce184a2..9dfc179 100644
--- a/backend/src/test/java/share/fare/backend/controller/GroupChatControllerTest.java
+++ b/backend/src/test/java/share/fare/backend/controller/GroupChatControllerTest.java
@@ -115,7 +115,7 @@ public void getRecentMessagesUserNotInGroupTest() throws Exception {
                         .param("size", "20")
                         .with(user(testSecondUser))
                 )
-                .andExpect(status().isConflict())
+                .andExpect(status().isForbidden())
                 .andExpect(jsonPath("$.message").value("User " + testSecondUser.getId() + " is not in group " + testGroup.getName()));
     }
 }
diff --git a/backend/src/test/java/share/fare/backend/controller/GroupInvitationControllerTest.java b/backend/src/test/java/share/fare/backend/controller/GroupInvitationControllerTest.java
index c44a7c7..7e12e78 100644
--- a/backend/src/test/java/share/fare/backend/controller/GroupInvitationControllerTest.java
+++ b/backend/src/test/java/share/fare/backend/controller/GroupInvitationControllerTest.java
@@ -173,7 +173,7 @@ void sendGroupInvitationSenderNotInGroupTest() throws Exception {
                         .principal(() -> String.valueOf(testUser.getId()))
                         .param("receiverId", String.valueOf(testSecondUser.getId()))
                         .param("groupId", String.valueOf(testGroup.getId())))
-                .andExpect(status().isConflict())
+                .andExpect(status().isForbidden())
                 .andExpect(jsonPath("$.message").value("Sender does not belong to group."));
     }
 
diff --git a/backend/src/test/java/share/fare/backend/controller/GroupMembershipControllerTest.java b/backend/src/test/java/share/fare/backend/controller/GroupMembershipControllerTest.java
index c869bc7..2cab320 100644
--- a/backend/src/test/java/share/fare/backend/controller/GroupMembershipControllerTest.java
+++ b/backend/src/test/java/share/fare/backend/controller/GroupMembershipControllerTest.java
@@ -171,7 +171,7 @@ void removeNonMemberTest() throws Exception {
         mockMvc.perform(delete(URI + "/{userId}", testGroup.getId(), newUser.getId())
                         .with(user(testUser))
                         .principal(() -> String.valueOf(testUser.getId())))
-                .andExpect(status().isConflict());
+                .andExpect(status().isForbidden());
     }
 
     @Test
diff --git a/backend/src/test/java/share/fare/backend/controller/VoteControllerTest.java b/backend/src/test/java/share/fare/backend/controller/VoteControllerTest.java
index cc962a6..122a876 100644
--- a/backend/src/test/java/share/fare/backend/controller/VoteControllerTest.java
+++ b/backend/src/test/java/share/fare/backend/controller/VoteControllerTest.java
@@ -140,7 +140,7 @@ void addVoteNotGroupMemberTest() throws Exception {
                         .content(objectMapper.writeValueAsString(voteRequest))
                         .with(user(anotherUser))
                         .principal(() -> String.valueOf(anotherUser.getId())))
-                .andExpect(status().isConflict())
+                .andExpect(status().isForbidden())
                 .andExpect(jsonPath("$.message").value("User with ID: " + anotherUser.getId() +" is not a member of the group"));
     }
 
diff --git a/frontend/app/(root)/trips/[id]/bill-splitting/page.tsx b/frontend/app/(root)/trips/[id]/bill-splitting/page.tsx
index 84ff3f0..3825d7a 100644
--- a/frontend/app/(root)/trips/[id]/bill-splitting/page.tsx
+++ b/frontend/app/(root)/trips/[id]/bill-splitting/page.tsx
@@ -57,7 +57,7 @@ export default function GroupExpensesPage() {
   useEffect(() => {
     if (!trip || !trip.id) return;
     fetchData();
-  });
+  }, [trip]);
 
   const fetchData = async () => {
     try {
diff --git a/frontend/components/bill-splitting/ExpensesDashboard.tsx b/frontend/components/bill-splitting/ExpensesDashboard.tsx
index 508ce87..7992851 100644
--- a/frontend/components/bill-splitting/ExpensesDashboard.tsx
+++ b/frontend/components/bill-splitting/ExpensesDashboard.tsx
@@ -34,7 +34,7 @@ export default function ExpansesDashboard({ trip }: { trip: Group }) {
 
   useEffect(() => {
     fetchGroupExpenses();
-  }, []);
+  }, [trip]);
 
   if (error) {
     return (
diff --git a/frontend/lib/axiosInstance.ts b/frontend/lib/axiosInstance.ts
index 8a4951d..4ab3119 100644
--- a/frontend/lib/axiosInstance.ts
+++ b/frontend/lib/axiosInstance.ts
@@ -20,4 +20,19 @@ axiosInstance.interceptors.request.use(
   },
 );
 
+axiosInstance.interceptors.response.use(
+  (response) => response,
+  (error) => {
+    if (
+      error.response &&
+      (error.response.status === 403 || error.response.status === 409)
+    ) {
+      if (typeof window !== 'undefined') {
+        window.location.href = '/trips';
+      }
+    }
+    return Promise.reject(error);
+  },
+);
+
 export default axiosInstance;