diff --git a/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpdateHistoricalFoodStockRequest.php b/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpdateHistoricalFoodStockRequest.php
index d137b168..caa5e853 100644
--- a/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpdateHistoricalFoodStockRequest.php
+++ b/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpdateHistoricalFoodStockRequest.php
@@ -17,10 +17,9 @@ class UpdateHistoricalFoodStockRequest extends FormRequest
         return [
             'variants' => ['required', 'array', 'min:1', 'max:500'],
             'stock_adjustment_id' => ['nullable', 'uuid'],
-            'variants.*' => ['required', 'array:id,stock,stock_difference'],
+            'variants.*' => ['required', 'array:id,stock_difference'],
             'variants.*.id' => ['required', 'integer', 'distinct'],
-            'variants.*.stock' => ['required', 'integer', 'min:0'],
-            'variants.*.stock_difference' => ['nullable', 'integer'],
+            'variants.*.stock_difference' => ['required', 'integer'],
         ];
     }
 }
diff --git a/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertAccommodationVariantsRequest.php b/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertAccommodationVariantsRequest.php
index 11ff365c..7e2475eb 100644
--- a/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertAccommodationVariantsRequest.php
+++ b/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertAccommodationVariantsRequest.php
@@ -3,6 +3,7 @@
 namespace App\Domains\Ticketing\FiestaFutbolInfantil\Requests;
 
 use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Validation\Validator;
 
 class UpsertAccommodationVariantsRequest extends FormRequest
 {
@@ -21,9 +22,37 @@ class UpsertAccommodationVariantsRequest extends FormRequest
             'variants.*.id' => ['sometimes', 'nullable', 'integer', 'distinct'],
             'variants.*.title' => ['required', 'string', 'max:255'],
             'variants.*.description' => ['sometimes', 'nullable', 'string'],
-            'variants.*.stock' => ['required', 'integer', 'min:0'],
-            'variants.*.stock_difference' => ['nullable', 'integer'],
+            'variants.*.stock' => ['sometimes', 'integer', 'min:0'],
+            'variants.*.stock_difference' => ['sometimes', 'integer'],
             'variants.*.price' => ['required', 'numeric', 'min:0', 'max:99999999.99'],
         ];
     }
+
+    /** @return array<int, callable> */
+    public function after(): array
+    {
+        return [
+            function (Validator $validator): void {
+                foreach ($this->input('variants', []) as $index => $variant) {
+                    if (! is_array($variant)) {
+                        continue;
+                    }
+
+                    if (isset($variant['id']) && ! array_key_exists('stock_difference', $variant)) {
+                        $validator->errors()->add(
+                            "variants.{$index}.stock_difference",
+                            'La diferencia de stock es obligatoria al actualizar una variante.',
+                        );
+                    }
+
+                    if (! isset($variant['id']) && ! array_key_exists('stock', $variant)) {
+                        $validator->errors()->add(
+                            "variants.{$index}.stock",
+                            'El stock inicial es obligatorio al crear una variante.',
+                        );
+                    }
+                }
+            },
+        ];
+    }
 }
diff --git a/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertEntriesRequest.php b/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertEntriesRequest.php
index b18cf1f3..2b982850 100644
--- a/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertEntriesRequest.php
+++ b/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertEntriesRequest.php
@@ -47,8 +47,8 @@ class UpsertEntriesRequest extends FormRequest
                     fn ($query) => $query->where('tenant_code', $tenantCode)
                 ),
             ],
-            'entries.*.stock' => ['required', 'integer', 'min:0'],
-            'entries.*.stock_difference' => ['nullable', 'integer'],
+            'entries.*.stock' => ['sometimes', 'integer', 'min:0'],
+            'entries.*.stock_difference' => ['sometimes', 'integer'],
             'entries.*.price' => ['required', 'numeric', 'min:0', 'max:99999999.99'],
         ];
     }
@@ -63,6 +63,20 @@ class UpsertEntriesRequest extends FormRequest
                         continue;
                     }
 
+                    if (isset($entry['id']) && ! array_key_exists('stock_difference', $entry)) {
+                        $validator->errors()->add(
+                            "entries.{$index}.stock_difference",
+                            'La diferencia de stock es obligatoria al actualizar una entrada.',
+                        );
+                    }
+
+                    if (! isset($entry['id']) && ! array_key_exists('stock', $entry)) {
+                        $validator->errors()->add(
+                            "entries.{$index}.stock",
+                            'El stock inicial es obligatorio al crear una entrada.',
+                        );
+                    }
+
                     $dateIds = $entry['event_date_ids'] ?? [];
 
                     if (! is_array($dateIds)) {
diff --git a/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertFoodVariantsRequest.php b/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertFoodVariantsRequest.php
index 1f6872ec..50b557d5 100644
--- a/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertFoodVariantsRequest.php
+++ b/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertFoodVariantsRequest.php
@@ -33,8 +33,8 @@ class UpsertFoodVariantsRequest extends FormRequest
             'variants.*.schedule' => ['required', 'string', 'max:255'],
             'variants.*.service' => ['required', 'string', 'max:255'],
             'variants.*.description' => ['sometimes', 'nullable', 'string'],
-            'variants.*.stock' => ['required', 'integer', 'min:0'],
-            'variants.*.stock_difference' => ['nullable', 'integer'],
+            'variants.*.stock' => ['sometimes', 'integer', 'min:0'],
+            'variants.*.stock_difference' => ['sometimes', 'integer'],
             'variants.*.price' => ['required', 'numeric', 'min:0', 'max:99999999.99'],
         ];
     }
@@ -51,6 +51,20 @@ class UpsertFoodVariantsRequest extends FormRequest
                         continue;
                     }
 
+                    if (isset($variant['id']) && ! array_key_exists('stock_difference', $variant)) {
+                        $validator->errors()->add(
+                            "variants.{$index}.stock_difference",
+                            'La diferencia de stock es obligatoria al actualizar una variante.',
+                        );
+                    }
+
+                    if (! isset($variant['id']) && ! array_key_exists('stock', $variant)) {
+                        $validator->errors()->add(
+                            "variants.{$index}.stock",
+                            'El stock inicial es obligatorio al crear una variante.',
+                        );
+                    }
+
                     $key = implode('|', [
                         $variant['event_date_id'] ?? '',
                         mb_strtolower(trim((string) ($variant['schedule'] ?? ''))),
diff --git a/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertMerchandiseRequest.php b/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertMerchandiseRequest.php
index 15b05967..0e683413 100644
--- a/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertMerchandiseRequest.php
+++ b/app/Domains/Ticketing/FiestaFutbolInfantil/Requests/UpsertMerchandiseRequest.php
@@ -4,6 +4,7 @@ namespace App\Domains\Ticketing\FiestaFutbolInfantil\Requests;
 
 use Illuminate\Foundation\Http\FormRequest;
 use Illuminate\Validation\Rule;
+use Illuminate\Validation\Validator;
 
 class UpsertMerchandiseRequest extends FormRequest
 {
@@ -44,9 +45,44 @@ class UpsertMerchandiseRequest extends FormRequest
             'items.*.variants.*.id' => ['sometimes', 'nullable', 'integer', 'distinct'],
             'items.*.variants.*.color' => ['required', 'string', 'max:255'],
             'items.*.variants.*.size' => ['required', 'string', 'max:255'],
-            'items.*.variants.*.stock' => ['required', 'integer', 'min:0'],
-            'items.*.variants.*.stock_difference' => ['nullable', 'integer'],
+            'items.*.variants.*.stock' => ['sometimes', 'integer', 'min:0'],
+            'items.*.variants.*.stock_difference' => ['sometimes', 'integer'],
             'items.*.variants.*.price' => ['required', 'numeric', 'min:0', 'max:99999999.99'],
         ];
     }
+
+    /** @return array<int, callable> */
+    public function after(): array
+    {
+        return [
+            function (Validator $validator): void {
+                foreach ($this->input('items', []) as $itemIndex => $item) {
+                    if (! is_array($item)) {
+                        continue;
+                    }
+
+                    foreach ($item['variants'] ?? [] as $variantIndex => $variant) {
+                        if (! is_array($variant)) {
+                            continue;
+                        }
+
+                        $prefix = "items.{$itemIndex}.variants.{$variantIndex}";
+                        if (isset($variant['id']) && ! array_key_exists('stock_difference', $variant)) {
+                            $validator->errors()->add(
+                                "{$prefix}.stock_difference",
+                                'La diferencia de stock es obligatoria al actualizar una variante.',
+                            );
+                        }
+
+                        if (! isset($variant['id']) && ! array_key_exists('stock', $variant)) {
+                            $validator->errors()->add(
+                                "{$prefix}.stock",
+                                'El stock inicial es obligatorio al crear una variante.',
+                            );
+                        }
+                    }
+                }
+            },
+        ];
+    }
 }
diff --git a/app/Domains/Ticketing/FiestaFutbolInfantil/Services/AccommodationService.php b/app/Domains/Ticketing/FiestaFutbolInfantil/Services/AccommodationService.php
index 20e44ee6..4e33b50e 100644
--- a/app/Domains/Ticketing/FiestaFutbolInfantil/Services/AccommodationService.php
+++ b/app/Domains/Ticketing/FiestaFutbolInfantil/Services/AccommodationService.php
@@ -169,7 +169,7 @@ class AccommodationService
             'title' => trim($variant['title']),
             'value' => $this->valueCode($variant['title']),
             'description' => $variant['description'] ?? null,
-            'stock' => (int) $variant['stock'],
+            ...(array_key_exists('stock', $variant) ? ['stock' => (int) $variant['stock']] : []),
         ])->all();
     }
 
@@ -257,8 +257,10 @@ class AccommodationService
             'descripcion' => $data['description'],
             'precio' => $data['price'],
         ]);
-        $stockDifference = (int) ($data['stock_difference'] ?? ($data['stock'] - $inventory->availableStock()));
-        $inventory->adjustAvailableStock($stockDifference, idempotencyKey: $stockAdjustmentId);
+        $inventory->adjustAvailableStock(
+            (int) $data['stock_difference'],
+            idempotencyKey: $stockAdjustmentId,
+        );
         $variant->definitions()->updateOrCreate(
             ['item_attribute_id' => $itemAttribute->id],
             ['value' => $data['value']],
diff --git a/app/Domains/Ticketing/FiestaFutbolInfantil/Services/EntryService.php b/app/Domains/Ticketing/FiestaFutbolInfantil/Services/EntryService.php
index 5c486029..06ac4e09 100644
--- a/app/Domains/Ticketing/FiestaFutbolInfantil/Services/EntryService.php
+++ b/app/Domains/Ticketing/FiestaFutbolInfantil/Services/EntryService.php
@@ -141,8 +141,10 @@ class EntryService
         $catalogItem->itemAttributes()
             ->whereHas('attribute', fn ($query) => $query->where('codigo', 'event_date'))
             ->update(['allow_multi_select' => true]);
-        $stockDifference = (int) ($entry['stock_difference'] ?? ((int) $entry['stock'] - $inventory->availableStock()));
-        $inventory->adjustAvailableStock($stockDifference, idempotencyKey: $stockAdjustmentId);
+        $inventory->adjustAvailableStock(
+            (int) $entry['stock_difference'],
+            idempotencyKey: $stockAdjustmentId,
+        );
 
         return $catalogItem->load([
             'variants.inventory',
diff --git a/app/Domains/Ticketing/FiestaFutbolInfantil/Services/FoodService.php b/app/Domains/Ticketing/FiestaFutbolInfantil/Services/FoodService.php
index 8b9f4c05..1e194eaf 100644
--- a/app/Domains/Ticketing/FiestaFutbolInfantil/Services/FoodService.php
+++ b/app/Domains/Ticketing/FiestaFutbolInfantil/Services/FoodService.php
@@ -113,7 +113,7 @@ class FoodService
     }
 
     /**
-     * @param  array<int, array{id: int, stock: int}>  $variants
+     * @param  array<int, array{id: int, stock_difference: int}>  $variants
      */
     public function updateHistoricalStock(Tenant $tenant, array $variants, ?string $stockAdjustmentId = null): CatalogItem
     {
@@ -143,8 +143,10 @@ class FoodService
                 }
 
                 $inventory = $this->inventoryForHistoricalStockUpdate($variant);
-                $stockDifference = (int) ($data['stock_difference'] ?? ((int) $data['stock'] - $inventory->availableStock()));
-                $inventory->adjustAvailableStock($stockDifference, idempotencyKey: $stockAdjustmentId);
+                $inventory->adjustAvailableStock(
+                    (int) $data['stock_difference'],
+                    idempotencyKey: $stockAdjustmentId,
+                );
             }
 
             return $this->current($tenant) ?? $food;
@@ -294,7 +296,7 @@ class FoodService
                 'schedule' => $schedule->value,
                 'service' => $service->value,
                 'description' => (string) ($variant['description'] ?? ''),
-                'stock' => (int) $variant['stock'],
+                ...(array_key_exists('stock', $variant) ? ['stock' => (int) $variant['stock']] : []),
             ];
         })->all();
     }
@@ -407,8 +409,10 @@ class FoodService
             'precio' => $data['price'],
         ]);
         $variant->eventDates()->sync([$data['event_date_id']]);
-        $stockDifference = (int) ($data['stock_difference'] ?? ($data['stock'] - $inventory->availableStock()));
-        $inventory->adjustAvailableStock($stockDifference, idempotencyKey: $stockAdjustmentId);
+        $inventory->adjustAvailableStock(
+            (int) $data['stock_difference'],
+            idempotencyKey: $stockAdjustmentId,
+        );
         $this->syncDefinitions($variant, $itemAttributes, $data);
     }
 
diff --git a/app/Domains/Ticketing/FiestaFutbolInfantil/Services/MerchandiseService.php b/app/Domains/Ticketing/FiestaFutbolInfantil/Services/MerchandiseService.php
index 735406df..9beaac2d 100644
--- a/app/Domains/Ticketing/FiestaFutbolInfantil/Services/MerchandiseService.php
+++ b/app/Domains/Ticketing/FiestaFutbolInfantil/Services/MerchandiseService.php
@@ -245,7 +245,7 @@ class MerchandiseService
                 ...$variant,
                 'color' => $color->value,
                 'size' => $size->value,
-                'stock' => (int) $variant['stock'],
+                ...(array_key_exists('stock', $variant) ? ['stock' => (int) $variant['stock']] : []),
             ];
         })->all();
     }
@@ -369,8 +369,10 @@ class MerchandiseService
             ->firstOrFail();
 
         $variant->update(['precio' => $data['price']]);
-        $stockDifference = (int) ($data['stock_difference'] ?? ($data['stock'] - $inventory->availableStock()));
-        $inventory->adjustAvailableStock($stockDifference, idempotencyKey: $stockAdjustmentId);
+        $inventory->adjustAvailableStock(
+            (int) $data['stock_difference'],
+            idempotencyKey: $stockAdjustmentId,
+        );
         $this->syncDefinitions($variant, $itemAttributes, $data);
     }
 
diff --git a/tests/Feature/FiestaFutbolInfantil/AccommodationControllerTest.php b/tests/Feature/FiestaFutbolInfantil/AccommodationControllerTest.php
index d04907fb..3050ac09 100644
--- a/tests/Feature/FiestaFutbolInfantil/AccommodationControllerTest.php
+++ b/tests/Feature/FiestaFutbolInfantil/AccommodationControllerTest.php
@@ -97,6 +97,8 @@ class AccommodationControllerTest extends TestCase
 
         $updated = $this->variantPayload('Casa Rodante Premium', 'Con electricidad', 15, 50000);
         $updated['id'] = $variantId;
+        unset($updated['stock']);
+        $updated['stock_difference'] = -5;
 
         $this->postJson('/api/v1/adminapp/tenant/accommodations', [
             'variants' => [
diff --git a/tests/Feature/FiestaFutbolInfantil/EntryControllerTest.php b/tests/Feature/FiestaFutbolInfantil/EntryControllerTest.php
index fb3b59fb..b6066fe9 100644
--- a/tests/Feature/FiestaFutbolInfantil/EntryControllerTest.php
+++ b/tests/Feature/FiestaFutbolInfantil/EntryControllerTest.php
@@ -194,7 +194,7 @@ class EntryControllerTest extends TestCase
                     'title' => 'Abono actualizado',
                     'description' => 'Ahora incluye ambas fechas',
                     'event_date_ids' => [$firstDate->id, $secondDate->id],
-                    'stock' => 20,
+                    'stock_difference' => 10,
                     'price' => 250,
                 ],
                 [
@@ -268,7 +268,7 @@ class EntryControllerTest extends TestCase
                 'id' => $entryId,
                 'title' => 'Abono editado',
                 'event_date_ids' => [$date->id, $otherDate->id],
-                'stock' => 30,
+                'stock_difference' => 10,
                 'price' => 200,
             ]],
         ])->assertOk()
@@ -329,7 +329,7 @@ class EntryControllerTest extends TestCase
                 'title' => 'Entrada inválida',
                 'description' => null,
                 'event_date_ids' => [$foreignDate->id],
-                'stock' => 10,
+                'stock_difference' => 0,
                 'price' => 100,
             ]],
         ])
@@ -371,7 +371,7 @@ class EntryControllerTest extends TestCase
                 'title' => 'Entrada inválida',
                 'description' => null,
                 'event_date_ids' => [$eventDate->id],
-                'stock' => 10,
+                'stock_difference' => 0,
                 'price' => 100,
             ]],
         ])
diff --git a/tests/Feature/FiestaFutbolInfantil/FoodControllerTest.php b/tests/Feature/FiestaFutbolInfantil/FoodControllerTest.php
index bef74360..c0339163 100644
--- a/tests/Feature/FiestaFutbolInfantil/FoodControllerTest.php
+++ b/tests/Feature/FiestaFutbolInfantil/FoodControllerTest.php
@@ -124,6 +124,8 @@ class FoodControllerTest extends TestCase
 
         $updated = $this->variantPayload($secondDate->id, 'Cena', 'Vianda', 80, 8500);
         $updated['id'] = $variantId;
+        unset($updated['stock']);
+        $updated['stock_difference'] = -20;
         $updated['description'] = 'Cena para llevar';
 
         $this->postJson('/api/v1/adminapp/tenant/foods', [
@@ -240,7 +242,7 @@ class FoodControllerTest extends TestCase
         Inventory::query()->whereKey($replacementInventoryId)->delete();
 
         $updated = $this->patchJson('/api/v1/adminapp/tenant/foods/history-stock', [
-            'variants' => [['id' => $historicalVariantId, 'stock' => 45]],
+            'variants' => [['id' => $historicalVariantId, 'stock_difference' => -55]],
         ])
             ->assertOk()
             ->assertJsonPath('data.history.0.variants.0.id', $historicalVariantId)
@@ -258,7 +260,7 @@ class FoodControllerTest extends TestCase
         ]);
 
         $this->patchJson('/api/v1/adminapp/tenant/foods/history-stock', [
-            'variants' => [['id' => $activeVariantId, 'stock' => 20]],
+            'variants' => [['id' => $activeVariantId, 'stock_difference' => -60]],
         ])
             ->assertUnprocessable()
             ->assertJsonValidationErrors(['variants.0.id']);
diff --git a/tests/Feature/FiestaFutbolInfantil/MerchandiseControllerTest.php b/tests/Feature/FiestaFutbolInfantil/MerchandiseControllerTest.php
index 09752a40..7f8ddcf8 100644
--- a/tests/Feature/FiestaFutbolInfantil/MerchandiseControllerTest.php
+++ b/tests/Feature/FiestaFutbolInfantil/MerchandiseControllerTest.php
@@ -112,6 +112,8 @@ class MerchandiseControllerTest extends TestCase
 
         $updatedVariant = $this->variantPayload('Blanco', 'M', 80, 12500);
         $updatedVariant['id'] = $variantId;
+        unset($updatedVariant['stock']);
+        $updatedVariant['stock_difference'] = -20;
         $updatedItem = $this->itemPayload('Camiseta oficial', 2, [
             $updatedVariant,
             $this->variantPayload('Verde', 'L', 60, 15000),
@@ -234,6 +236,8 @@ class MerchandiseControllerTest extends TestCase
         $secondItemVariantId = $created->json('data.1.variants.0.id');
         $foreignVariant = $this->variantPayload('Azul Marino', 'XL', 20, 30000);
         $foreignVariant['id'] = $secondItemVariantId;
+        unset($foreignVariant['stock']);
+        $foreignVariant['stock_difference'] = 0;
         $firstItem = $this->itemPayload('Camiseta', 3, [$foreignVariant]);
         $firstItem['id'] = $firstItemId;