diff --git a/src/Service/AccommodationBookingPdfGenerator.php b/src/Service/AccommodationBookingPdfGenerator.php
index caf4f72..395a361 100644
--- a/src/Service/AccommodationBookingPdfGenerator.php
+++ b/src/Service/AccommodationBookingPdfGenerator.php
@@ -11,7 +11,6 @@ use Dompdf\Options;
 use Symfony\Component\DependencyInjection\Attribute\Autowire;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpFoundation\ResponseHeaderBag;
-use Symfony\Component\String\Slugger\AsciiSlugger;
 use Twig\Environment;
 
 /**
@@ -81,10 +80,6 @@ class AccommodationBookingPdfGenerator
         return $response;
     }
 
-    /**
-     * Named after arrival date and group rather than the entity id, which is a local
-     * detail with no counterpart in BusPro and would read as a booking number.
-     */
     /**
      * @throws \RuntimeException when the booking carries no price information
      */
@@ -95,14 +90,13 @@ class AccommodationBookingPdfGenerator
 
     private function buildFilename(AccommodationBooking $booking): string
     {
-        $groupName = (new AsciiSlugger('de'))->slug((string) $booking->getGroupName())->lower()->toString();
+        $parts = array_filter([
+            $booking->getDateFrom()?->format('Y-m-d'),
+            $booking->getAccommodation()?->getCalendarCode(),
+            'Buchung',
+        ]);
 
-        return sprintf(
-            '%s-%s%s.pdf',
-            mb_strtolower($booking->recordLabel()),
-            $booking->getDateFrom()?->format('Y-m-d') ?? 'ohne-datum',
-            '' !== $groupName ? '-'.$groupName : ''
-        );
+        return implode(' ', $parts).'.pdf';
     }
 
     private function logoDataUri(): string
diff --git a/tests/Service/AccommodationBookingPdfGeneratorTest.php b/tests/Service/AccommodationBookingPdfGeneratorTest.php
index 3d480a9..d95e4a7 100644
--- a/tests/Service/AccommodationBookingPdfGeneratorTest.php
+++ b/tests/Service/AccommodationBookingPdfGeneratorTest.php
@@ -27,26 +27,26 @@ class AccommodationBookingPdfGeneratorTest extends TestCase
         self::assertSame(1, $this->pageCount($pdf));
     }
 
-    public function testTheDownloadIsAnAttachmentNamedAfterTheGroup(): void
+    public function testTheDownloadIsAnAttachmentNamedAfterArrivalDateAndHotel(): void
     {
         $response = $this->createGenerator($this->breakdown())->createDownloadResponse($this->booking());
 
         self::assertSame('application/pdf', $response->headers->get('Content-Type'));
         self::assertStringContainsString('attachment;', (string) $response->headers->get('Content-Disposition'));
-        self::assertStringContainsString('buchung-2026-07-06-schulklasse-7b.pdf', (string) $response->headers->get('Content-Disposition'));
+        self::assertStringContainsString('2026-07-06 BERGBLICK Buchung.pdf', (string) $response->headers->get('Content-Disposition'));
     }
 
-    public function testADocumentForAnUnacceptedOfferIsNamedAsOne(): void
+    public function testADocumentForAnUnacceptedOfferKeepsTheSameFilename(): void
     {
-        // The document describes whatever the record is at the time it is produced, so it
-        // must not call an offer nobody has accepted a booking.
+        // 'Buchung' in the filename is a literal, not the record label: the office files
+        // these documents by date and house, and a second spelling would break that order.
         $booking = $this->booking();
         $booking->setAcceptedAt(null);
         $booking->setConfirmedAt(null);
 
         $response = $this->createGenerator($this->breakdown())->createDownloadResponse($booking);
 
-        self::assertStringContainsString('angebot-2026-07-06-schulklasse-7b.pdf', (string) $response->headers->get('Content-Disposition'));
+        self::assertStringContainsString('2026-07-06 BERGBLICK Buchung.pdf', (string) $response->headers->get('Content-Disposition'));
     }
 
     public function testABookingWithoutPricesCannotBeRendered(): void
@@ -74,6 +74,7 @@ class AccommodationBookingPdfGeneratorTest extends TestCase
     {
         $accommodation = new Accommodation();
         $accommodation->setName('Haus Bergblick');
+        $accommodation->setCalendarCode('BERGBLICK');
         $accommodation->setMaxAdolescentAge(11);
         $accommodation->setCurrency('EUR');