Open the card under My cards and press Reveal Details to see the number, expiry and security code. They are rendered straight from the issuer's vault into your browser, so they never pass through our servers. Enter them at checkout as you would any card — with one difference that catches most people out: use the billing address shown on that same page, not your own. Merchants check the card's address, and yours will be declined. If the merchant asks for a one-time code, it appears as a banner at the top of your dashboard.