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Using Test Credit Cards

Simulate credit card payments to test your integration.

In a sandbox environment, developers and merchants can test the integration and functionality of their payment systems without processing actual financial transactions.

To simulate real transactions in sandbox, test credit cards are used. This guide provides step-by-step instructions on how to effectively use test credit cards in a sandbox environment for testing purposes.

Test cards let you simulate several scenarios such as:

  • Successful payments by card brand / country
  • Card errors due to declines, fraud or invalid data
  • Disputes and refunds
  • Authentication with 3DS and PINs

How to use test cards

When you work with a test card, please ensure you use test API keys in all API calls within Hello Clever.


Do not use real card details. Testing in live mode using real payment method details is highly discouraged.

Testing within the UI

When testing interactively in our payment gateway, you can use a test card number such as 4242 4242 4242 4242.

  • Use a valid future date for card's expiration date.
  • Use any 3 digit CVC or 4 digits for AMEX cards
  • Use any value you prefer for other form fields.
Cards by brand

To simulate a successul payment, you can use any of the test cards from the table below.

Visa4242 4242 4242 4242Any 3 digitsAny future date
Visa Debit4000 0566 5566 5556Any 3 digitsAny future date
Mastercard5555 5555 5555 4444Any 3 digitsAny future date
American Express3782 822463 10005Any 4 digitsAny future date
JCB3566 0020 2036 0505Any 3 digitsAny future date