diff --git a/firebase/functions/src/types.ts b/firebase/functions/src/types.ts
index 89b6132..84d49eb 100644
--- a/firebase/functions/src/types.ts
+++ b/firebase/functions/src/types.ts
@@ -1,9 +1,9 @@
-export const messageTypes = ['text', 'system', 'timeProposal'] as const;
+export const messageTypes = ["text", "system", "timeProposal"] as const;
 export type MessageType = (typeof messageTypes)[number];
 
 // TimeOfDay string type matching Flutter's TimeFormatter.productionToString format
 // Format: "TimeOfDay(HH:MM)" where HH and MM are zero-padded
-type Digit = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9';
+type Digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9";
 export type TimeOfDayString = `TimeOfDay(${Digit}${Digit}:${Digit}${Digit})`;
 
 // Base message fields shared by all message types
@@ -15,19 +15,19 @@ type BaseMessage = {
 };
 
 export type TextMessage = BaseMessage & {
-  messageType: 'text';
+  messageType: "text";
   content: string;
 };
 
 export type SystemMessage = BaseMessage & {
-  messageType: 'system';
+  messageType: "system";
   content: string;
 };
 
 export type TimeProposal = BaseMessage & {
-  messageType: 'timeProposal';
+  messageType: "timeProposal";
   proposedTime: TimeOfDayString;
-  status: 'pending' | 'accepted' | 'rejected';
+  status: "pending" | "accepted" | "rejected";
 };
 
 export type Message = TextMessage | SystemMessage | TimeProposal;
@@ -67,4 +67,4 @@ export type User = {
   fcmToken?: string;
   isEmailVerified: boolean;
   // other fields aren't relevant
-};
\ No newline at end of file
+};
diff --git a/swipeshare_app/lib/pages/buy/buy_swipes.dart b/swipeshare_app/lib/pages/buy/buy_swipes.dart
index 301b24a..067a87f 100644
--- a/swipeshare_app/lib/pages/buy/buy_swipes.dart
+++ b/swipeshare_app/lib/pages/buy/buy_swipes.dart
@@ -8,7 +8,6 @@ import 'package:swipeshare_app/components/buy_and_sell_screens/time_picker.dart'
 import 'package:swipeshare_app/components/buy_and_sell_screens/time_picker_validation.dart';
 import 'package:swipeshare_app/components/colors.dart';
 import 'package:swipeshare_app/components/text_styles.dart';
-import 'package:swipeshare_app/models/user.dart';
 import 'package:swipeshare_app/pages/buy/listing_selection_page.dart';
 import 'package:swipeshare_app/utils/haptics.dart';
 
@@ -128,7 +127,7 @@ class _BuySwipeScreenState extends State<BuySwipeScreen> {
     return SizedBox(
       width: double.infinity,
       child: ElevatedButton(
-        onPressed: _canProceedToNextScreen()
+        onPressed: _canProceedToSelection()
             ? _navigateToListingSelection
             : null,
         style: ElevatedButton.styleFrom(
@@ -157,10 +156,11 @@ class _BuySwipeScreenState extends State<BuySwipeScreen> {
   }
 
   /// Validates if user can proceed to next screen
-  bool _canProceedToNextScreen() {
+  bool _canProceedToSelection() {
     return startTime != null &&
         endTime != null &&
         selectedLocations.isNotEmpty &&
+        selectedPaymentOptions.isNotEmpty &&
         !_isEndTimeBeforeStartTime();
   }
 
@@ -176,9 +176,7 @@ class _BuySwipeScreenState extends State<BuySwipeScreen> {
             date: selectedDate,
             startTime: startTime!,
             endTime: endTime!,
-            paymentTypes: selectedPaymentOptions.isEmpty
-                ? PaymentOption.allPaymentTypeNames
-                : selectedPaymentOptions,
+            paymentTypes: selectedPaymentOptions,
           ),
         ),
       );
diff --git a/swipeshare_app/lib/pages/onboarding/login_page.dart b/swipeshare_app/lib/pages/onboarding/login_page.dart
index eef5b07..8b8ec71 100644
--- a/swipeshare_app/lib/pages/onboarding/login_page.dart
+++ b/swipeshare_app/lib/pages/onboarding/login_page.dart
@@ -24,6 +24,18 @@ class _LoginPageState extends State<LoginPage> {
 
   //sign in user
   void signIn() async {
+    // Validate that email and password are not empty
+    if (emailController.text.trim().isEmpty ||
+        passwordController.text.isEmpty) {
+      await safeVibrate(HapticsType.error);
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          const SnackBar(content: Text('Please enter both email and password')),
+        );
+      }
+      return;
+    }
+
     //get the auth service
     final authService = Provider.of<AuthServices>(context, listen: false);
 
@@ -36,9 +48,10 @@ class _LoginPageState extends State<LoginPage> {
     } catch (e) {
       await safeVibrate(HapticsType.error);
       if (mounted) {
+        final errorMessage = e.toString().replaceFirst('Exception: ', '');
         ScaffoldMessenger.of(
           context,
-        ).showSnackBar(SnackBar(content: Text(e.toString())));
+        ).showSnackBar(SnackBar(content: Text(errorMessage)));
       }
     }
   }
diff --git a/swipeshare_app/lib/pages/onboarding/signup_page.dart b/swipeshare_app/lib/pages/onboarding/signup_page.dart
index ff899fa..e1c524a 100644
--- a/swipeshare_app/lib/pages/onboarding/signup_page.dart
+++ b/swipeshare_app/lib/pages/onboarding/signup_page.dart
@@ -29,6 +29,18 @@ class _RegisterPageState extends State<RegisterPage> {
 
   //sign up user
   void signUp() async {
+    // Validate that all required fields are filled out
+    if (nameController.text.trim().isEmpty ||
+        emailController.text.trim().isEmpty ||
+        passwordController.text.isEmpty ||
+        confirmPasswordController.text.isEmpty) {
+      await safeVibrate(HapticsType.error);
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(content: Text('Please fill out all required fields')),
+      );
+      return;
+    }
+
     // make it unc email only
     if (!emailController.text.trim().toLowerCase().endsWith('unc.edu') ||
         (!referralController.text.trim().toLowerCase().endsWith('unc.edu') &&
@@ -83,18 +95,13 @@ class _RegisterPageState extends State<RegisterPage> {
         nameController.text,
         referralController.text,
       );
-      if (mounted) {
-        await safeVibrate(HapticsType.medium);
-        // Navigator.pushReplacement(
-        //   context,
-        //   MaterialPageRoute(builder: (context) => OnboardingCarousel()),
-        // );
-      }
+      await safeVibrate(HapticsType.medium);
     } catch (e) {
+      final errorMessage = e.toString().replaceFirst('Exception: ', '');
       if (mounted) {
         ScaffoldMessenger.of(
           context,
-        ).showSnackBar(SnackBar(content: Text(e.toString())));
+        ).showSnackBar(SnackBar(content: Text(errorMessage)));
       }
     }
   }
diff --git a/swipeshare_app/lib/services/auth/auth_services.dart b/swipeshare_app/lib/services/auth/auth_services.dart
index 34f69b6..22e9f8c 100644
--- a/swipeshare_app/lib/services/auth/auth_services.dart
+++ b/swipeshare_app/lib/services/auth/auth_services.dart
@@ -27,7 +27,7 @@ class AuthServices extends ChangeNotifier {
 
       return userCredential;
     } on FirebaseAuthException catch (e) {
-      throw Exception(e.code);
+      throw Exception(_getAuthErrorMessage(e.code));
     }
   }
 
@@ -56,12 +56,7 @@ class AuthServices extends ChangeNotifier {
 
       return userCredential;
     } on FirebaseAuthException catch (e) {
-      //catch errors
-      // debugPrint('Error code: ${e.code}');
-      // debugPrint('Error message: ${e.message}');
-      // debugPrint('Error details: ${e.stackTrace}');
-
-      throw Exception(e.code);
+      throw Exception(_getAuthErrorMessage(e.code));
     }
   }
 
@@ -72,4 +67,30 @@ class AuthServices extends ChangeNotifier {
     await FirebaseAuth.instance.signOut();
     debugPrint('User signed out successfully.');
   }
+
+  //convert Firebase auth error codes to user-friendly messages
+  String _getAuthErrorMessage(String code) {
+    switch (code) {
+      case 'invalid-credential':
+        return 'Invalid email or password. Please try again.';
+      case 'user-not-found':
+        return 'No account found with this email.';
+      case 'wrong-password':
+        return 'Incorrect password. Please try again.';
+      case 'email-already-in-use':
+        return 'This email is already registered.';
+      case 'weak-password':
+        return 'Password is too weak. Please use a stronger password.';
+      case 'invalid-email':
+        return 'Invalid email address format.';
+      case 'user-disabled':
+        return 'This account has been disabled.';
+      case 'too-many-requests':
+        return 'Too many failed attempts. Please try again later.';
+      case 'network-request-failed':
+        return 'Network error. Please check your connection.';
+      default:
+        return 'An error occurred. Please try again.';
+    }
+  }
 }
diff --git a/swipeshare_app/lib/services/order_service.dart b/swipeshare_app/lib/services/order_service.dart
index 31656e3..560533b 100644
--- a/swipeshare_app/lib/services/order_service.dart
+++ b/swipeshare_app/lib/services/order_service.dart
@@ -14,9 +14,9 @@ class OrderService extends ChangeNotifier {
   //POST ORDER
   Future<MealOrder> postOrder(Listing listing) async {
     try {
-      final result = await _functions.httpsCallable('createOrderFromListing').call({
-        'listingId': listing.id,
-      });
+      final result = await _functions
+          .httpsCallable('createOrderFromListing')
+          .call({'listingId': listing.id});
 
       final orderData = result.data as Map<String, dynamic>;
       final newOrder = MealOrder.fromMap(orderData);