Michael Nardy, industry leader, Chief Executive Officer of Electronic Payments Inc. (EPI) and member of our advisory board, kindly offered the following answer to your question:

"The first (and best) source for this information is your processor. The heart of your question deals with 'downgrades,' and they should be able to provide you with a bucket assignment spreadsheet (the key for understanding where your processor places each category of interchange: qual, mid, non, etc.)

"In addition, they should have the most recent interchange qualification guides, which are the guides that show what information is required and what prompts must be inputted to qualify a transaction in a certain interchange category. Other sources are the Visa Inc. and MasterCard Worldwide Web sites.

"While Visa's site displays the interchange rates in PDF format, MasterCard has a lengthy guide, which not only shows the rates, but the MCC codes that are eligible for those rates, the percent variance between auth and settle amounts, the time frame within which the transaction must be settled, and what magnetic stripe and authorization data must be obtained."

For further information, try checking GS Online's MLS Forum. It contains lively discussions about interchange and other topics of interest to ISOs and MLSs. To get there, visit www.greensheet.com and click Forums. You'll need to follow a brief sign-up procedure to participate.