# Test payment transactions This section describes how to test payment transactions in Rebilly using the sandbox environment and TestProcessor gateway. ## Overview Testing payments in Rebilly involves using test card numbers, configuring test environments, and simulating various transaction scenarios. No real charges are made when testing in the sandbox environment. Test payment cards, IBANs, and ACH details Simulate different payment outcomes in the sandbox environment using test payment cards, IBANs, and ACH details. Run test transactions in the sandbox Test your integration in the sandbox environment. Test a generic offsite approval flow Simulate a generic offsite approval flow. Test a 3ds challenge flow Simulate a 3DS challenge flow. Environment and live checklist Learn about Rebilly environments and the go live checklist.