You can use the Circle API [sandbox environment](🔗) to exercise various types of card payment behaviors, such as authorization failure codes and address verification results.
To get your desired behavior:
Use one of the test numbers listed below
Choose a specific payment amount, CVV code, or address value
# Eligible Card Numbers
No Real Charges
The [sandbox environment](🔗) will authorize card payments made with any card number, but it will **never actually verify or charge the card**.
To make payments on the sandbox environment please use one of the provided test card numbers below, using other card numbers will return an error response.
|Card number||Card provider|
# Response Codes
To trigger specific response codes, use the corresponding amounts below when creating a payment. Any amount not specified in the table will return `
Approved` (response code `
|5.01||payment_failed||Payment failed due to unspecified error|
|5.04||card_not_honored||Contact card issuer to query why payment failed|
|5.05||payment_not_supported_by_issuer||Issuer did not support the payment|
|5.07||payment_not_funded||Insufficient funds in account to fund payment|
|5.19||card_invalid||Invalid card number|
|5.41||card_limit_violated||Exceeded amount or frequency limits|
|5.43||payment_denied||Payment denied by Circle Risk Service or card processor risk controls|
|5.51||payment_fraud_detected||Payment suspected of being associated with fraud|
|5.54||credit_card_not_allowed||Issuer did not support using a credit card for payment|
|5.57||payment_stopped_by_issuer||A stop has been placed on the payment or card|
|5.84||card_account_ineligible||Ineligible account associated with card|
# CVV Verification
For more information on the card verification value (CVV) check and return values see the [verifying card details guide](🔗).
Setting the CVV to `
000` or `
999` will cause a CVV failure response.
# AVS Verification
For more information on the address verification service (AVS) check and the possible return codes see [verifying card details guide](🔗).
To trigger a particular AVS check result, set the address line 1 field to `
Test_X`, where `
X` is one of the available AVS return codes. The result defaults to AVS code `