diff --git a/app/Http/Controllers/Repuve/CancellationController.php b/app/Http/Controllers/Repuve/CancellationController.php
index d04bc87..183fc47 100644
--- a/app/Http/Controllers/Repuve/CancellationController.php
+++ b/app/Http/Controllers/Repuve/CancellationController.php
@@ -93,19 +93,19 @@ public function cancelarConstancia(CancelConstanciaRequest $request)
                     ]);
                 }
 
-                // Usar el folio del NUEVO TAG
-                $newTag->markAsAssigned($vehicle->id, $newTag->folio);
+                // Usar el folio del request
+                $newTag->markAsAssigned($vehicle->id, $request->folio);
 
                 $substitutionLog = VehicleTagLog::create([
                     'vehicle_id' => $vehicle->id,
                     'tag_id' => $newTag->id,
                     'action_type' => 'sustitucion',
                     'cancellation_reason' => $request->cancellation_reason,
-                    'cancellation_observations' => 'Tag sustituido. Tag anterior: ' . $oldTagNumber . 'Motivo: ' . ($request->cancellation_observations ?? ''),
+                    'cancellation_observations' => 'Tag sustituido. Tag anterior: ' . $oldTagNumber . ' (Folio: ' . $oldFolio . '). Motivo: ' . ($request->cancellation_observations ?? ''),
                     'performed_by' => Auth::id(),
                 ]);
 
-                $record->update(['folio' => $newTag->folio]);
+                $record->update(['folio' => $request->folio]);
             }
 
             DB::commit();
diff --git a/app/Http/Requests/Repuve/CancelConstanciaRequest.php b/app/Http/Requests/Repuve/CancelConstanciaRequest.php
index 9f3a30c..fcebc3d 100644
--- a/app/Http/Requests/Repuve/CancelConstanciaRequest.php
+++ b/app/Http/Requests/Repuve/CancelConstanciaRequest.php
@@ -21,6 +21,7 @@ public function rules(): array
     {
         return [
             'record_id' => 'required|exists:records,id',
+            'folio' => 'required|string',
             'cancellation_reason' => 'required|in:fallo_lectura_handheld,cambio_parabrisas,roto_al_pegarlo,extravio,otro',
             'cancellation_observations' => 'nullable|string',
             'new_tag_number' => 'nullable|exists:tags,tag_number',
diff --git a/app/Models/Tag.php b/app/Models/Tag.php
index 0f01dc5..7bc97f2 100644
--- a/app/Models/Tag.php
+++ b/app/Models/Tag.php
@@ -72,7 +72,7 @@ public function markAsCancelled(): void
         $this->update([
             'status_id' => $statusCancelled->id,
             'vehicle_id' => null,
-            'folio' => null,
+            // Mantener el folio porque la columna no acepta null
         ]);
     }