diff --git a/apps/mobile/packages/core_localization/lib/src/l10n/en.i18n.json b/apps/mobile/packages/core_localization/lib/src/l10n/en.i18n.json
index be7f2b3a..5645f0c3 100644
--- a/apps/mobile/packages/core_localization/lib/src/l10n/en.i18n.json
+++ b/apps/mobile/packages/core_localization/lib/src/l10n/en.i18n.json
@@ -1479,7 +1479,9 @@
     },
     "clock_in": {
       "location_verification_required": "Please wait for location verification before clocking in.",
-      "notes_required_for_timeout": "Please add a note explaining why your location can't be verified."
+      "notes_required_for_timeout": "Please add a note explaining why your location can't be verified.",
+      "already_clocked_in": "You're already clocked in to this shift.",
+      "already_clocked_out": "You've already clocked out of this shift."
     },
     "generic": {
       "unknown": "Something went wrong. Please try again.",
diff --git a/apps/mobile/packages/core_localization/lib/src/l10n/es.i18n.json b/apps/mobile/packages/core_localization/lib/src/l10n/es.i18n.json
index 420d0ef6..389f4e87 100644
--- a/apps/mobile/packages/core_localization/lib/src/l10n/es.i18n.json
+++ b/apps/mobile/packages/core_localization/lib/src/l10n/es.i18n.json
@@ -1474,7 +1474,9 @@
     },
     "clock_in": {
       "location_verification_required": "Por favor, espera la verificaci\u00f3n de ubicaci\u00f3n antes de registrar entrada.",
-      "notes_required_for_timeout": "Por favor, agrega una nota explicando por qu\u00e9 no se puede verificar tu ubicaci\u00f3n."
+      "notes_required_for_timeout": "Por favor, agrega una nota explicando por qu\u00e9 no se puede verificar tu ubicaci\u00f3n.",
+      "already_clocked_in": "Ya est\u00e1s registrado en este turno.",
+      "already_clocked_out": "Ya registraste tu salida de este turno."
     },
     "generic": {
       "unknown": "Algo sali\u00f3 mal. Por favor, intenta de nuevo.",
diff --git a/apps/mobile/packages/features/staff/clock_in/lib/src/presentation/bloc/clock_in/clock_in_bloc.dart b/apps/mobile/packages/features/staff/clock_in/lib/src/presentation/bloc/clock_in/clock_in_bloc.dart
index 4661fae4..9a6e9f06 100644
--- a/apps/mobile/packages/features/staff/clock_in/lib/src/presentation/bloc/clock_in/clock_in_bloc.dart
+++ b/apps/mobile/packages/features/staff/clock_in/lib/src/presentation/bloc/clock_in/clock_in_bloc.dart
@@ -204,29 +204,49 @@ class ClockInBloc extends Bloc<ClockInEvent, ClockInState>
       action: () async {
         final DeviceLocation? location = geofenceState.currentLocation;
 
-        final AttendanceStatus newStatus = await _clockIn(
-          ClockInArguments(
-            shiftId: event.shiftId,
-            notes: event.notes,
-            latitude: location?.latitude,
-            longitude: location?.longitude,
-            accuracyMeters: location?.accuracy,
-            capturedAt: location?.timestamp,
-            overrideReason: geofenceState.isGeofenceOverridden
-                ? geofenceState.overrideNotes
-                : null,
-          ),
-        );
-        emit(state.copyWith(
-          status: ClockInStatus.success,
-          attendance: newStatus,
-        ));
+        try {
+          final AttendanceStatus newStatus = await _clockIn(
+            ClockInArguments(
+              shiftId: event.shiftId,
+              notes: event.notes,
+              latitude: location?.latitude,
+              longitude: location?.longitude,
+              accuracyMeters: location?.accuracy,
+              capturedAt: location?.timestamp,
+              overrideReason: geofenceState.isGeofenceOverridden
+                  ? geofenceState.overrideNotes
+                  : null,
+            ),
+          );
+          emit(state.copyWith(
+            status: ClockInStatus.success,
+            attendance: newStatus,
+          ));
 
-        // Start background tracking after successful clock-in.
-        _dispatchBackgroundTrackingStarted(
-          event: event,
-          activeShiftId: newStatus.activeShiftId,
-        );
+          // Start background tracking after successful clock-in.
+          _dispatchBackgroundTrackingStarted(
+            event: event,
+            activeShiftId: newStatus.activeShiftId,
+          );
+        } on AppException catch (_) {
+          // The clock-in API call failed. Re-fetch attendance status to
+          // reconcile: if the worker is already clocked in (e.g. duplicate
+          // session from Postgres constraint 23505), treat it as success.
+          final AttendanceStatus currentStatus = await _getAttendanceStatus();
+          if (currentStatus.isClockedIn) {
+            emit(state.copyWith(
+              status: ClockInStatus.success,
+              attendance: currentStatus,
+            ));
+            _dispatchBackgroundTrackingStarted(
+              event: event,
+              activeShiftId: currentStatus.activeShiftId,
+            );
+          } else {
+            // Worker is genuinely not clocked in — surface the error.
+            rethrow;
+          }
+        }
       },
       onError: (String errorKey) => state.copyWith(
         status: ClockInStatus.failure,
@@ -261,29 +281,51 @@ class ClockInBloc extends Bloc<ClockInEvent, ClockInState>
         final GeofenceState currentGeofence = _geofenceBloc.state;
         final DeviceLocation? location = currentGeofence.currentLocation;
 
-        final AttendanceStatus newStatus = await _clockOut(
-          ClockOutArguments(
-            notes: event.notes,
-            breakTimeMinutes: event.breakTimeMinutes,
-            shiftId: activeShiftId,
-            latitude: location?.latitude,
-            longitude: location?.longitude,
-            accuracyMeters: location?.accuracy,
-            capturedAt: location?.timestamp,
-          ),
-        );
-        emit(state.copyWith(
-          status: ClockInStatus.success,
-          attendance: newStatus,
-        ));
+        try {
+          final AttendanceStatus newStatus = await _clockOut(
+            ClockOutArguments(
+              notes: event.notes,
+              breakTimeMinutes: event.breakTimeMinutes,
+              shiftId: activeShiftId,
+              latitude: location?.latitude,
+              longitude: location?.longitude,
+              accuracyMeters: location?.accuracy,
+              capturedAt: location?.timestamp,
+            ),
+          );
+          emit(state.copyWith(
+            status: ClockInStatus.success,
+            attendance: newStatus,
+          ));
 
-        // Stop background tracking after successful clock-out.
-        _geofenceBloc.add(
-          BackgroundTrackingStopped(
-            clockOutTitle: event.clockOutTitle,
-            clockOutBody: event.clockOutBody,
-          ),
-        );
+          // Stop background tracking after successful clock-out.
+          _geofenceBloc.add(
+            BackgroundTrackingStopped(
+              clockOutTitle: event.clockOutTitle,
+              clockOutBody: event.clockOutBody,
+            ),
+          );
+        } on AppException catch (_) {
+          // The clock-out API call failed. Re-fetch attendance status to
+          // reconcile: if the worker is already clocked out (e.g. duplicate
+          // end-session), treat it as success.
+          final AttendanceStatus currentStatus = await _getAttendanceStatus();
+          if (!currentStatus.isClockedIn) {
+            emit(state.copyWith(
+              status: ClockInStatus.success,
+              attendance: currentStatus,
+            ));
+            _geofenceBloc.add(
+              BackgroundTrackingStopped(
+                clockOutTitle: event.clockOutTitle,
+                clockOutBody: event.clockOutBody,
+              ),
+            );
+          } else {
+            // Worker is still clocked in — surface the error.
+            rethrow;
+          }
+        }
       },
       onError: (String errorKey) => state.copyWith(
         status: ClockInStatus.failure,