PURCHASE, N.Y. — Both Visa and MasterCard have recently broken with a long tradition of secrecy when it comes to how their interchange rates on credit and debit card transactions are set by posting them up on the Internet for merchants to examine. Interchange is the money that card issuers and brands charge merchants as a fee for being able to accept their cards. It has been the subject of political and legal pressure for years as merchants have accused the brands of keeping the charges too high and having a monopoly on the credit card industry. MasterCard was the latest brand to take the step, posting 72 pages of interchange rates and what's behind them, at a special Web site, www.mastercardmerchant.com. The company had previously promised to begin posting the information no later than Nov. 1. Visa has already posted a five-page document on its Web site that lays out interchange rates. It has also posted its operating regulations. However, Visa restricted access to its operating regulations to merchants that have contracts with Visa and have agreed to signed nondisclosure agreements. MasterCard appeared to make the change with a concern that providing the information could lead to more confusion than it cleared up.

"Although MasterCard's U.S. interchange rates have generally been available to merchants both through requests to merchant acquirers and independent sales organizations, and on the Internet, the merchant community has asked us for greater transparency, and we are pleased to accommodate their request," explained Walt Macnee, president for the Americas region for MasterCard.

"Just publishing rates alone could lead to confusion among merchants who may be seeing this information for the first time," Macnee noted. "We are confident that we are providing merchants with the information they need to understand the interchange rates and structure and determine which rates may apply to their transactions. We want to have an ongoing dialogue with merchants, acquirers and other interested parties about the format and content of our rate disclosure, as we plan to update this document regularly."