You may wish not to charge a customer, but only to authorize their card. This is quite useful in various scenarios, for example:
- getting the card number when a customer signs up for a free trial (you can charge them later automatically),
- checking the credit card (for example whether online transactions are not blocked),
- confirming the card when a customer creates an account in your e-store (for example if you wish to allow Card Data Storage).
Authorizing a card means blocking a specific amount for some time on the customer’s card. You can either block the whole amount (and capture the funds later) or you can block just $1 (or €1, or £1, or…) just to verify the card.
Start with preparing data required to perform the authorization. Note that the data comes in exactly the same format as when performing a regular transaction. You can choose whether to authorize for just one euro, dollar, pound (or any other currency), or for the whole amount (if you’re planning to capture the funds later).