Chase is about to throw a major wrench in your retention program.

According to payment processing expert Paul Larsen, Chase has entered into a strategic partnership with Visa and will be changing all of its customers over from MasterCard to Visa.

That means that 16 million current MasterCard users will receive new cards with new account numbers from Chase over the next year. That averages to more than one million cards re-issued each month!

And while Chase is looking to make the transition easy for consumers, subscription sites are likely to be heavily affected as the new account numbers will increase the rate of card declines for recurring billing and auto-renewal.

In this week’s How-To on Subscription Site Insider, we detail how Account Updater is best way for subscriptions sites to thwart a massive decline in renewals and revenues. (Account Updater is a program that automatically updates credit cards without consumers having to enter their new information.)

However, not all payment processors offer Account Updater, and even Chase Paymenttech (that’s right, the payment processor owned by Chase Bank) gives conflicting information when you call its sales line. (A previous blog post talks about how to deal with this problem.)

If you can’t get Account Updater, then you have other options, like a strong renewal campaign via email and phone. Just don’t make the mistake of thinking this massive re-issuance won’t affect your bottom line in 2014.