diff --git a/db/README.md b/db/README.md
index 56192f3..1b71e4a 100644
--- a/db/README.md
+++ b/db/README.md
@@ -6,6 +6,7 @@
 2. `db/migrations/0002_phase1_seed_methods.sql`
 3. `db/migrations/0003_phase1_inventory_forecast.sql`
 4. `db/migrations/0004_phase1_direct_sales.sql`
+5. `db/migrations/0005_phase1_auto_switch_fix.sql`
 
 ## Beispielausfuehrung
 
@@ -14,6 +15,7 @@ psql "$DATABASE_URL" -f db/migrations/0001_phase1_core.sql
 psql "$DATABASE_URL" -f db/migrations/0002_phase1_seed_methods.sql
 psql "$DATABASE_URL" -f db/migrations/0003_phase1_inventory_forecast.sql
 psql "$DATABASE_URL" -f db/migrations/0004_phase1_direct_sales.sql
+psql "$DATABASE_URL" -f db/migrations/0005_phase1_auto_switch_fix.sql
 ```
 
 ## Enthaltene Kernlogik in `0001`
diff --git a/db/migrations/0001_phase1_core.sql b/db/migrations/0001_phase1_core.sql
index bfdb9e4..0f17af4 100644
--- a/db/migrations/0001_phase1_core.sql
+++ b/db/migrations/0001_phase1_core.sql
@@ -665,7 +665,10 @@ BEGIN
   END IF;
 
   UPDATE stock_lot
-  SET status = 'current', updated_at = NOW()
+  SET
+    status = 'current',
+    lot_number = COALESCE(lot_number, format('AUTO-%s-%s', v_product_id, v_open_lot_id)),
+    updated_at = NOW()
   WHERE id = v_open_lot_id;
 
   INSERT INTO stock_lot (product_id, lot_number, status)
diff --git a/db/migrations/0005_phase1_auto_switch_fix.sql b/db/migrations/0005_phase1_auto_switch_fix.sql
new file mode 100644
index 0000000..1e0d67c
--- /dev/null
+++ b/db/migrations/0005_phase1_auto_switch_fix.sql
@@ -0,0 +1,99 @@
+BEGIN;
+
+-- Fix lot auto-switch when current lot reaches zero:
+-- if the next open lot has no lot_number yet, assign one before switching to status=current.
+-- This avoids violating chk_stock_lot_number_required_for_non_open.
+
+CREATE OR REPLACE FUNCTION fn_auto_switch_lot_when_depleted()
+RETURNS TRIGGER
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  v_product_id BIGINT;
+  v_open_lot_id BIGINT;
+  v_current_net NUMERIC;
+  v_event_key TEXT;
+BEGIN
+  -- only relevant when the updated lot is currently active
+  SELECT product_id
+  INTO v_product_id
+  FROM stock_lot
+  WHERE id = NEW.lot_id;
+
+  -- if lot is not current anymore, nothing to do
+  IF NOT EXISTS (
+    SELECT 1 FROM stock_lot WHERE id = NEW.lot_id AND status = 'current'
+  ) THEN
+    RETURN NEW;
+  END IF;
+
+  SELECT qty_net
+  INTO v_current_net
+  FROM v_stock_lot_balance
+  WHERE stock_lot_id = NEW.lot_id;
+
+  IF COALESCE(v_current_net, 0) > 0 THEN
+    RETURN NEW;
+  END IF;
+
+  -- lock all lots for this product to avoid race conditions
+  PERFORM 1
+  FROM stock_lot
+  WHERE product_id = v_product_id
+  FOR UPDATE;
+
+  -- confirm current lot is still current after lock
+  IF NOT EXISTS (
+    SELECT 1 FROM stock_lot WHERE id = NEW.lot_id AND status = 'current'
+  ) THEN
+    RETURN NEW;
+  END IF;
+
+  UPDATE stock_lot
+  SET status = 'closed', updated_at = NOW()
+  WHERE id = NEW.lot_id;
+
+  SELECT id
+  INTO v_open_lot_id
+  FROM stock_lot
+  WHERE product_id = v_product_id
+    AND status = 'open'
+  ORDER BY id
+  LIMIT 1
+  FOR UPDATE;
+
+  IF v_open_lot_id IS NULL THEN
+    RAISE EXCEPTION 'No open lot available for product % during auto switch', v_product_id;
+  END IF;
+
+  -- current/closed lots must have a lot_number due to chk_stock_lot_number_required_for_non_open.
+  UPDATE stock_lot
+  SET
+    status = 'current',
+    lot_number = COALESCE(lot_number, format('AUTO-%s-%s', v_product_id, v_open_lot_id)),
+    updated_at = NOW()
+  WHERE id = v_open_lot_id;
+
+  INSERT INTO stock_lot (product_id, lot_number, status)
+  VALUES (v_product_id, NULL, 'open');
+
+  v_event_key := format('lot.auto_switched:%s:%s', v_product_id, txid_current());
+
+  PERFORM fn_enqueue_event(
+    'lot.auto_switched',
+    v_event_key,
+    'stock_lot',
+    NEW.lot_id::TEXT,
+    jsonb_build_object(
+      'productId', v_product_id,
+      'closedLotId', NEW.lot_id,
+      'newCurrentLotId', v_open_lot_id,
+      'occurredAt', NOW()
+    )
+  );
+
+  RETURN NEW;
+END;
+$$;
+
+COMMIT;
diff --git a/order-import.php b/order-import.php
index cb9a2a9..ae2b7c2 100644
--- a/order-import.php
+++ b/order-import.php
@@ -437,6 +437,27 @@ function normalize_title_key(string $value): string
     return $value;
 }
 
+function normalize_match_key(string $value): string
+{
+    $value = trim($value);
+    if ($value === '') {
+        return '';
+    }
+
+    $ascii = $value;
+    if (function_exists('iconv')) {
+        $converted = iconv('UTF-8', 'ASCII//TRANSLIT//IGNORE', $value);
+        if (is_string($converted) && $converted !== '') {
+            $ascii = $converted;
+        }
+    }
+
+    $ascii = strtolower($ascii);
+    $ascii = preg_replace('/[^a-z0-9]+/', ' ', $ascii) ?? $ascii;
+    $ascii = preg_replace('/\s+/', ' ', trim($ascii)) ?? $ascii;
+    return $ascii;
+}
+
 function find_existing_order_id(PDO $pdo, string $externalRef): ?int
 {
     $stmt = $pdo->prepare('SELECT id FROM public.sales_order WHERE external_ref = :external_ref LIMIT 1');
@@ -582,9 +603,234 @@ function resolve_product_id_fallback(PDO $pdo, string $articleNumber, string $ti
         }
     }
 
+    // Business fallback for known product families where Wix title differs from ERP product label.
+    $search = normalize_match_key($articleNumber . ' ' . $title);
+    if ($search !== '') {
+        $familyPatterns = [];
+
+        if (str_contains($search, 'lion') || str_contains($search, 'mane')) {
+            $familyPatterns[] = '%lionsmane%';
+            $familyPatterns[] = '%lion%';
+        }
+        if (str_contains($search, 'shiitake')) {
+            $familyPatterns[] = '%shiitake%';
+        }
+        if (str_contains($search, 'chaga')) {
+            $familyPatterns[] = '%chaga%';
+        }
+        if (str_contains($search, 'reishi')) {
+            $familyPatterns[] = '%reishi%';
+        }
+
+        foreach ($familyPatterns as $pattern) {
+            $stmt = $pdo->prepare(
+                'SELECT id
+                 FROM public.product
+                 WHERE lower(name) LIKE :pattern
+                 ORDER BY id
+                 LIMIT 1'
+            );
+            $stmt->execute([':pattern' => $pattern]);
+            $id = $stmt->fetchColumn();
+            if ($id !== false) {
+                return (int) $id;
+            }
+        }
+    }
+
     return null;
 }
 
+function sellable_item_exists(PDO $pdo, int $sellableItemId): bool
+{
+    $stmt = $pdo->prepare('SELECT 1 FROM public.sellable_item WHERE id = :id LIMIT 1');
+    $stmt->execute([':id' => $sellableItemId]);
+    return $stmt->fetchColumn() !== false;
+}
+
+function find_sellable_item_for_product(PDO $pdo, int $productId): ?int
+{
+    $stmt = $pdo->prepare(
+        'SELECT sellable_item_id
+         FROM public.sellable_item_component
+         WHERE product_id = :product_id
+         ORDER BY id
+         LIMIT 1'
+    );
+    $stmt->execute([':product_id' => $productId]);
+    $id = $stmt->fetchColumn();
+    return $id === false ? null : (int) $id;
+}
+
+function find_product_name(PDO $pdo, int $productId): ?string
+{
+    $stmt = $pdo->prepare('SELECT name FROM public.product WHERE id = :id LIMIT 1');
+    $stmt->execute([':id' => $productId]);
+    $name = $stmt->fetchColumn();
+    if ($name === false) {
+        return null;
+    }
+    $name = trim((string) $name);
+    return $name === '' ? null : $name;
+}
+
+function ensure_unique_sellable_item_code(PDO $pdo, string $preferred): string
+{
+    $base = preg_replace('/[^A-Za-z0-9._-]+/', '-', trim($preferred)) ?? '';
+    $base = trim($base, '-');
+    if ($base === '') {
+        $base = 'AUTO-ITEM';
+    }
+    $base = strtoupper(substr($base, 0, 60));
+
+    $existsStmt = $pdo->prepare('SELECT 1 FROM public.sellable_item WHERE item_code = :item_code LIMIT 1');
+    $candidate = $base;
+    $suffix = 1;
+
+    while (true) {
+        $existsStmt->execute([':item_code' => $candidate]);
+        if ($existsStmt->fetchColumn() === false) {
+            return $candidate;
+        }
+
+        $suffix++;
+        $prefixMaxLen = max(1, 60 - strlen((string) $suffix) - 1);
+        $candidate = substr($base, 0, $prefixMaxLen) . '-' . $suffix;
+    }
+}
+
+function ensure_alias_points_to_sellable_item(
+    PDO $pdo,
+    int $sellableItemId,
+    string $articleNumber,
+    string $title
+): bool {
+    $articleNumber = trim($articleNumber);
+    $title = trim($title);
+    $titleNorm = normalize_title_key($title);
+
+    if ($articleNumber === '' && $title === '') {
+        return false;
+    }
+
+    $findExisting = $pdo->prepare(
+        "SELECT id, sellable_item_id
+         FROM public.external_item_alias
+         WHERE source_system = 'wix'
+           AND (
+             (:article_number <> '' AND external_article_number = :article_number)
+             OR (:title_norm <> '' AND title_normalized = :title_norm)
+             OR (:title <> '' AND lower(external_title) = lower(:title))
+           )
+         ORDER BY id
+         LIMIT 1
+         FOR UPDATE"
+    );
+    $findExisting->execute([
+        ':article_number' => $articleNumber,
+        ':title_norm' => $titleNorm,
+        ':title' => $title,
+    ]);
+    $existing = $findExisting->fetch();
+
+    if (is_array($existing)) {
+        $existingSellable = isset($existing['sellable_item_id']) ? (int) $existing['sellable_item_id'] : 0;
+        $aliasId = isset($existing['id']) ? (int) $existing['id'] : 0;
+        if ($existingSellable === $sellableItemId) {
+            $touchStmt = $pdo->prepare('UPDATE public.external_item_alias SET is_active = TRUE, updated_at = NOW() WHERE id = :id');
+            $touchStmt->execute([':id' => $aliasId]);
+            return false;
+        }
+
+        $updateStmt = $pdo->prepare(
+            'UPDATE public.external_item_alias
+             SET sellable_item_id = :sellable_item_id,
+                 external_article_number = :article_number,
+                 external_title = :title,
+                 title_normalized = :title_norm,
+                 is_active = TRUE,
+                 updated_at = NOW()
+             WHERE id = :id'
+        );
+        $updateStmt->execute([
+            ':sellable_item_id' => $sellableItemId,
+            ':article_number' => $articleNumber !== '' ? $articleNumber : null,
+            ':title' => $title !== '' ? $title : null,
+            ':title_norm' => $titleNorm !== '' ? $titleNorm : null,
+            ':id' => $aliasId,
+        ]);
+        return true;
+    }
+
+    $insertStmt = $pdo->prepare(
+        "INSERT INTO public.external_item_alias (
+            source_system, external_article_number, external_title, title_normalized, sellable_item_id, is_active, created_at, updated_at
+         ) VALUES (
+            'wix', :article_number, :title, :title_norm, :sellable_item_id, TRUE, NOW(), NOW()
+         )"
+    );
+    $insertStmt->execute([
+        ':article_number' => $articleNumber !== '' ? $articleNumber : null,
+        ':title' => $title !== '' ? $title : null,
+        ':title_norm' => $titleNorm !== '' ? $titleNorm : null,
+        ':sellable_item_id' => $sellableItemId,
+    ]);
+    return true;
+}
+
+function ensure_sellable_mapping_from_product_fallback(
+    PDO $pdo,
+    int $productId,
+    string $articleNumber,
+    string $title
+): array {
+    $articleNumber = trim($articleNumber);
+    $title = trim($title);
+
+    $sellableItemId = find_sellable_item_for_product($pdo, $productId);
+    $createdSellable = false;
+    if ($sellableItemId === null || !sellable_item_exists($pdo, $sellableItemId)) {
+        $productName = find_product_name($pdo, $productId);
+        $itemCodeSeed = $articleNumber !== '' ? $articleNumber : "AUTO-PROD-{$productId}";
+        $itemCode = ensure_unique_sellable_item_code($pdo, $itemCodeSeed);
+        $displayName = $title !== '' ? $title : ($productName ?? $itemCode);
+
+        $insertSellable = $pdo->prepare(
+            'INSERT INTO public.sellable_item (item_code, display_name, status, created_at, updated_at)
+             VALUES (:item_code, :display_name, \'active\', NOW(), NOW())
+             RETURNING id'
+        );
+        $insertSellable->execute([
+            ':item_code' => $itemCode,
+            ':display_name' => $displayName,
+        ]);
+        $id = $insertSellable->fetchColumn();
+        if ($id === false) {
+            throw new RuntimeException("Could not create sellable_item for fallback product {$productId}");
+        }
+        $sellableItemId = (int) $id;
+        $createdSellable = true;
+    }
+
+    $insertComponent = $pdo->prepare(
+        'INSERT INTO public.sellable_item_component (sellable_item_id, product_id, qty_per_item, created_at, updated_at)
+         VALUES (:sellable_item_id, :product_id, 1.0, NOW(), NOW())
+         ON CONFLICT (sellable_item_id, product_id) DO NOTHING'
+    );
+    $insertComponent->execute([
+        ':sellable_item_id' => $sellableItemId,
+        ':product_id' => $productId,
+    ]);
+
+    $aliasChanged = ensure_alias_points_to_sellable_item($pdo, $sellableItemId, $articleNumber, $title);
+
+    return [
+        'sellableItemId' => $sellableItemId,
+        'createdSellableItem' => $createdSellable,
+        'aliasCreatedOrUpdated' => $aliasChanged,
+    ];
+}
+
 function get_current_lot_balance_for_update(PDO $pdo, int $productId): array
 {
     $lotStmt = $pdo->prepare(
@@ -638,10 +884,15 @@ function switch_current_lot(PDO $pdo, int $productId, int $oldCurrentLotId): int
 
     $makeCurrentStmt = $pdo->prepare(
         "UPDATE public.stock_lot
-         SET status = 'current', updated_at = NOW()
+         SET status = 'current',
+             lot_number = COALESCE(lot_number, :auto_lot_number),
+             updated_at = NOW()
          WHERE id = :id"
     );
-    $makeCurrentStmt->execute([':id' => (int) $newCurrentLotId]);
+    $makeCurrentStmt->execute([
+        ':id' => (int) $newCurrentLotId,
+        ':auto_lot_number' => 'AUTO-' . $productId . '-' . (int) $newCurrentLotId,
+    ]);
 
     $createOpenStmt = $pdo->prepare(
         "INSERT INTO public.stock_lot (product_id, lot_number, status, created_at, updated_at)
@@ -1037,6 +1288,19 @@ try {
         $unitPrice = parse_number($lineItem['preisEinheit'] ?? null);
         $lineTotal = $unitPrice !== null ? round($qty * $unitPrice, 2) : null;
         $sellableItemId = resolve_sellable_item_id($pdo, $articleNumber, $title);
+        $autoMappingMeta = null;
+        if ($sellableItemId === null) {
+            $fallbackProductId = resolve_product_id_fallback($pdo, $articleNumber, $title);
+            if ($fallbackProductId !== null) {
+                $autoMappingMeta = ensure_sellable_mapping_from_product_fallback(
+                    $pdo,
+                    $fallbackProductId,
+                    $articleNumber,
+                    $title
+                );
+                $sellableItemId = (int) $autoMappingMeta['sellableItemId'];
+            }
+        }
         $lineNo = $index + 1;
 
         $lineInsert->execute([
@@ -1056,29 +1320,13 @@ try {
         $lineId = (int) $lineId;
 
         if ($sellableItemId === null) {
-            $fallbackProductId = resolve_product_id_fallback($pdo, $articleNumber, $title);
-            if ($fallbackProductId !== null) {
-                $inventory['linesMappedViaFallbackProduct']++;
-                $allocationResult = allocate_line_inventory_fallback_product(
-                    $pdo,
-                    $orderId,
-                    $lineId,
-                    $lineNo,
-                    (float) $qty,
-                    $fallbackProductId,
-                    $locations
-                );
-                if ($allocationResult['allocated'] === false) {
-                    $inventory['warnings'][] = "Fallback product allocation missing for line {$lineNo}: " . $allocationResult['reason'];
-                } else {
-                    $inventory['allocationCount'] += count($allocationResult['allocations']);
-                    $inventory['warnings'][] = "Line {$lineNo} allocated via fallback product mapping (product_id={$fallbackProductId})";
-                }
-            } else {
-                $inventory['linesUnmapped']++;
-                $inventory['warnings'][] = "No sellable item mapping for line {$lineNo} (artikelnummer='{$articleNumber}', titel='{$title}')";
-            }
+            $inventory['linesUnmapped']++;
+            $inventory['warnings'][] = "No sellable item mapping for line {$lineNo} (artikelnummer='{$articleNumber}', titel='{$title}')";
         } else {
+            if (is_array($autoMappingMeta)) {
+                $inventory['linesMappedViaFallbackProduct']++;
+                $inventory['warnings'][] = "Line {$lineNo} auto-mapped from product fallback (sellable_item_id={$sellableItemId})";
+            }
             $inventory['linesMapped']++;
             $allocationResult = allocate_line_inventory(
                 $pdo,