diff --git a/frontend/src/__tests__/GuestPaymentRedirect.spec.ts b/frontend/src/__tests__/GuestPaymentRedirect.spec.ts
index 7e31b4b..81a606f 100644
--- a/frontend/src/__tests__/GuestPaymentRedirect.spec.ts
+++ b/frontend/src/__tests__/GuestPaymentRedirect.spec.ts
@@ -124,12 +124,16 @@ describe('GuestPaymentRedirect', () => {
     })
   })
 
-  it('renders QR code after loading swish info', async () => {
+  it('renders QR code with spec-compliant settings', async () => {
     const { wrapper } = await mountPage()
     await vi.waitFor(() => {
       expect(wrapper.find('.payment__qr-img').exists()).toBe(true)
     })
     expect(mockToDataURL).toHaveBeenCalledTimes(1)
+    const options = mockToDataURL.mock.calls[0][1]
+    expect(options.margin).toBe(4)
+    expect(options.width).toBe(288)
+    expect(options.color).toEqual({ dark: '#000000', light: '#ffffff' })
   })
 
   it('renders Swish payment link', async () => {
diff --git a/frontend/src/pages/GuestPaymentRedirect.vue b/frontend/src/pages/GuestPaymentRedirect.vue
index f3261b2..a4c8e67 100644
--- a/frontend/src/pages/GuestPaymentRedirect.vue
+++ b/frontend/src/pages/GuestPaymentRedirect.vue
@@ -52,9 +52,15 @@ onMounted(async () => {
 
     if (swishPaymentUrl.value) {
       qrDataUrl.value = await QRCode.toDataURL(swishPaymentUrl.value, {
-        width: 224,
-        margin: 2,
-        color: { dark: '#111827', light: '#ffffff' },
+        // Swish requires a reliably scannable black-on-white QR. The previous
+        // settings (margin 2, #111827, 224px) produced a 2-module quiet zone
+        // — half the QR spec minimum — which the Swish app's scanner fails to
+        // read when scanning off a screen. Use the spec-compliant 4-module
+        // quiet zone, pure black, and larger modules.
+        width: 288,
+        margin: 4,
+        errorCorrectionLevel: 'M',
+        color: { dark: '#000000', light: '#ffffff' },
       })
     }
   } catch {
@@ -269,8 +275,8 @@ async function confirmPayment() {
 }
 
 .payment__qr-img {
-  width: 224px;
-  height: 224px;
+  width: 288px;
+  height: 288px;
   border-radius: var(--radius-md);
   margin: 0 auto var(--space-sm);
 }