The process of checking the availability of funds to complete a credit card sale, an authorization is expected to result in a positive response and the generation of a six or seven digit authorization code as well as the setting aside of those funds and the reducing of the available credit of the cardholder by that amount. A negative authorization or decline can result when funds are unavailable, a card is over its limit or for other reasons.
UniPay Gateway: Open Source Payment Gateway
How to Choose the Best Payment Solution
How to Own a Payment Gateway
What is a Payment Gateway
What is Recurring Billing?
How Payments Work
What Should an Ideal Payment Platform for Investors Look Like?