FakecreditcardAbout American Express card numbers
American Express is different from Visa and Mastercard in two ways that matter for testing. First, it is both the network and, in its largest markets, including the US, the issuer of the card. Second, its card numbers break the usual rules: they are 15 digits long instead of 16 and are grouped 4-6-5 (for example 3782 822463 10005).
The security code is also different. Amex prints a 4-digit CID on the front of the card, above the number, instead of a 3-digit code on the back. A checkout form that hard-codes a 16-digit length or a 3-digit CVV will reject every Amex customer, which is why Amex numbers are a standard part of any payment test plan.
All American Express numbers start with 34 or 37. The generator above creates both and adds a random 4-digit CID; use the CVV field if your test needs a fixed value.
American Express card number format and example
| Starts with (IIN) | 34 and 37 |
|---|---|
| Number length | 15 digits |
| Typical layout | 3xxx xxxxxx xxxxx |
| Security code | 4-digit CID printed on the front |
| Check digit | Last digit, calculated with the Luhn (mod 10) algorithm |
| Network | American Express |
| Example (test number) | 3782 822463 10005 |
Official American Express sandbox test numbers
Payment gateways publish fixed test numbers that only work in their test mode. Use them when you need a predictable gateway response; use the generator above for bulk or randomized data.
| Gateway | Test number | |
|---|---|---|
| Stripe | 3782 822463 10005 | |
| Stripe | 3714 496353 98431 | |
| Braintree | 3782 822463 10005 |
Sources: the gateways' own documentation — Stripe, PayPal, Braintree, Adyen.
Amex test card numbers with CVV
An American Express test number needs a 4-digit security code (CID): a 3-digit code fails any form that checks the length for the brand. The generator adds a random 4-digit CID to every number; when a test needs a fixed value, type it (for example 1234) in the CVV field under “Expiry, CVV & output format”.
In gateway test modes, the documented Amex numbers — such as Stripe’s 3782 822463 10005 and 3714 496353 98431 — accept any 4-digit CID and any future expiry date. To check a number and its CID length together, paste both into the validator.
Need a billing address and ZIP code as well? Tick Add billing address & ZIP (US) above; how address (AVS) testing works is explained on the Visa generator page.
How to test American Express payments safely
- Check that your form accepts exactly 15 digits, groups them 4-6-5 as the customer types, and switches the security-code field to 4 digits as soon as the number starts with 34 or 37.
- Change one digit of a generated number — your form should now reject it, because the Luhn check fails. You can confirm why with the validator.
- Switch your payment provider to sandbox / test mode and use its documented test cards for authorization, decline and 3-D Secure scenarios.
- Never use real customer card numbers in development or staging environments.
Frequently asked questions
How many digits is an American Express card number?
15 digits, formatted as 4-6-5. It is the only major brand that uses 15 digits.
Why does American Express have a 4-digit CVV?
Amex uses a 4-digit card identification number (CID) printed on the front of the card. Your form should accept 4 digits when the number starts with 34 or 37.
What is the Amex test card number for Stripe?
Stripe documents 3782 822463 10005 and 3714 496353 98431, with any future expiry date and any 4-digit CID, in test mode only.
What does an American Express card number look like?
15 digits starting with 34 or 37, grouped 4-6-5 — for example the Stripe test number 3782 822463 10005. The 4-digit CID is printed on the front.
Can I buy something or start a free trial with a generated card?
No. A real payment needs an authorization from the issuing bank, and no bank has issued these numbers, so every charge is declined. Trying to pay with a number you do not own is fraud. Use them only in sandboxes, forms and test data.