Plan payment flow tests in a sandbox

Task: Plan how I test the checkout and payment flow of my shop before a release. Context: My shop is [shop type] on [platform or stack] and uses [payment provider] in [countries]. Customers pay by [payment methods]. I have [time available] and [number of people] people to test. Rules: - Test only in the provider's sandbox or test mode, with the test card numbers and accounts the provider publishes. Never use a real card or real customer data. - Cover a successful payment, a declined payment, a payment that needs extra confirmation, a refund, a double click on pay, an abandoned checkout, taxes and shipping totals, and the confirmation email. - Include checks that the order, the payment status and the stock stay in step when something fails halfway. - Say which test cases to find in the provider's own documentation, and do not state test card numbers or provider rules yourself. - Remind me that payment rules differ by country and to ask a qualified professional about compliance questions. Result: A table of at most 12 rows with the columns case, steps, expected result and who checks it, then a short go or no-go checklist of 5 items.