Fix SKU format not resolving {id} for new variants

CHANGELOG.md

@@ -2,7 +2,8 @@
 
 ## Unreleased
 
-- Fixed a bug where the deprecated `craft\commerce\services\ProductTypes::getEditableProductTypes()` method could still be called. ([#4349](https://github.com/craftcms/commerce/issues/4349)) 
+- Fixed a bug where the deprecated `craft\commerce\services\ProductTypes::getEditableProductTypes()` method could still be called. ([#4349](https://github.com/craftcms/commerce/issues/4349))
+- Fixed a bug where a variant's `skuFormat` containing `{id}` would generate a SKU missing that value for new variants.
 - Fixed a bug where adding a site during a project config apply could rewrite `project.yaml`. ([#4348](https://github.com/craftcms/commerce/issues/4348))
 
 ## 5.7.2 - 2026-08-12

src/elements/Variant.php

@@ -225,6 +225,12 @@ class Variant extends Purchasable implements NestedElementInterface
      */
     private ?string $_productTypeHandle = null;
 
+    /**
+     * @var bool Whether the SKU was auto-generated from a `skuFormat` containing `{id}` before this element had an ID,
+     * meaning it needs to be regenerated in [[afterAssignedId()]] once the ID is available.
+     */
+    private bool $_regenerateSkuAfterIdAssigned = false;
+
     /**
      * @throws InvalidConfigException
      */
@@ -727,6 +733,12 @@ public function updateSku(Product $product): void
             Craft::$app->language = $this->getSite()->language;
             $this->sku = Craft::$app->getView()->renderSandboxedObjectTemplate($type->skuFormat, $this);
 
+            // If the format references the element's own ID but it doesn't have one yet, the rendered SKU will be
+            // missing that value — flag it for regeneration once afterAssignedId() runs.
+            if (!$this->id && str_contains($type->skuFormat, '{id}')) {
+                $this->_regenerateSkuAfterIdAssigned = true;
+            }
+
             $skuExistsQuery = function(string $sku, ?int $id) {
                 $query = (new Query())
                     ->select(['sku'])
@@ -1257,6 +1269,12 @@ public function afterAssignedId(): void
 
         $product = $this->getOwner();
         $this->updateTitle($product);
+
+        if ($this->_regenerateSkuAfterIdAssigned) {
+            $this->_regenerateSkuAfterIdAssigned = false;
+            $this->sku = '';
+            $this->updateSku($product);
+        }
     }
 
     /**

tests/unit/elements/product/ProductTest.php

@@ -442,6 +442,32 @@ public function testSkuFormatDeduplicatesMultipleVariantsWithCollision(): void
         $this->setProductTypeSkuFormat(2001, null);
     }
 
+    /**
+     * @group Product
+     */
+    public function testSkuFormatWithIdIsRegeneratedAfterIdAssigned(): void
+    {
+        $this->setProductTypeSkuFormat(2001, 'SKU-{id}');
+
+        $product = new Product();
+        $product->title = 'SKU Format Id Test Product';
+        $product->typeId = 2001;
+        $product->enabled = false;
+
+        $variant = new Variant();
+        $variant->title = 'Test Variant';
+        // No SKU — format references {id}, which isn't available until after the element is saved
+
+        $product->setVariants([$variant]);
+        \Craft::$app->getElements()->saveElement($product, false);
+
+        $savedVariant = $product->getDefaultVariant();
+        self::assertEquals('SKU-' . $savedVariant->id, $savedVariant->sku);
+
+        \Craft::$app->getElements()->deleteElementById($product->id, Product::class, null, true);
+        $this->setProductTypeSkuFormat(2001, null);
+    }
+
     private function resetSkuSequence(string $baseSku): void
     {
         \Craft::$app->getDb()->createCommand()