Authorize.Net is a payment gateway service provider allowing merchants to accept credit card and electronic checks payments through their Web site and over an IP (Internet Protocol) connection. Authorize.Net claims a user base of over 212,000 merchants, which would make them the Internet's largest payment gateway service provider.
In November 2007 Cybersource purchased Authorize.Net for $565 million.. Authorize.Net was originally purchased in 2004 by Lightbridge for $82 Million.
Authorize.Net offers two ways to integrate their payment gateway services into a merchant's Web site. The first method is called the Simple Integration Method (SIM). As the name implies this method is the less technically complex of the two. Using the Simple Integration Method a merchant would send the customer to the Authorize.Net website where a secure order page will capture their transaction information. Upon completion of the transaction the customer is returned to the merchant's Web site. This method is usually preferred by small businesses who do not have the technical capabilities to do a more advanced integration.
The second method of integration is called the Advanced Integration Method (AIM). This method of integration is more complex but more powerful then the Simple Integration Method. The Advanced Integration Method utilizes the Authorize.Net API to process a transaction without the customer leaving the merchant's Web site. The customer is unaware of how the transaction is processed and the checkout process is seamless to them. This method is usually chosen by larger businesses that wish to present their Web site in a professional manner.
A common misperception about Authorize.Net is that they are a merchant account provider. Authorize.Net currently does not offer merchant accounts as a service. To use the payment gateway offered by Authorize.Net a merchant will need to establish a merchant account through a separate company.