Test SumUp Payment Flows

Match the test to the requested integration and changed behavior. Inspect an existing harness and credentials configuration before proposing new infrastructure. For a test-data question, provide the relevant card or amount directly; a full end-to-end matrix is useful only when the task calls for it.

Choose the scenario reference

Read sandbox scenarios for the selected flow:

• Online payments: test cards, frictionless/challenge authentication, and documented decline amounts.
• Reader SDK or Cloud API: physical cards or Virtual Solo, sandbox SDK login, minor-unit amounts, and specific decline simulations.
• Saved cards: sandbox tokenization through the Payment Widget, subsequent charges, and deactivation.

Check the linked current guide when its data or SDK requirements differ from the bundled reference. Online test cards do not replace a physical card in a reader test, and simulated decline amounts do not reproduce a disconnected device.

Establish the test merchant

Use sandbox merchants and credentials for simulated payments. Confirm the merchant selected by the actual app/API credential; switching merchants in the Dashboard alone does not switch SDK login. Keep secrets and raw card data out of logs. Store checkout/transaction IDs and attempt references for reconciliation.

Create online checkouts server-side with merchant_code. The standard decline amount is 11.00 in the documented flow's units; Cloud API represents 11.00 EUR as { "currency": "EUR", "minor_unit": 2, "value": 1100 }. Creating a checkout alone does not complete a payment.