Testing & test cards

Test mode is a full, isolated sandbox that settles instantly and never touches a real banking network. Use these deterministic test cards to reproduce every outcome — success and every decline — straight from the docs.

Your test keysk_test_…

Test / live mode

Everything exists twice. Which mode you're in is decided purely by your key: sk_test_… is the sandbox, sk_live_… is real. Test-mode data is free, unlimited, and separate from live.

Successful cards

4242 4242 4242 4242Visa — succeeds.
4000 0056 6556 5556Visa (debit) — succeeds.
5555 5555 5555 4444Mastercard — succeeds.
3782 822463 10005American Express — succeeds.

Use any future expiry (e.g. 12 / 34) and any 3-digit CVC.

Decline cards

4000 0000 0000 9995insufficient_funds
4000 0000 0000 0069expired_card
4000 0000 0000 0127incorrect_cvc
4000 0000 0000 0002card_declined (generic)

Try it end to end

Create an invoice, open its hosted page, and pay it with one of the cards above.

POST/v1/invoices

Run this, then click Open hosted page ↗ and pay with 4242… to watch invoice.paid fire.

cURLNodePython