GM Financial experienced servicing issues this month, including overcharging and undercharging customers and intermittent phone problems, Automotive News has learned.
The lender says the glitches developed following a sweeping computer system enhancement.
"I don't think there is a bigger endeavor that an auto finance company can do than to convert all of their servicing systems into one in one fell swoop," Bob Beatty, executive vice president of customer experience, told Automotive News. "It was as big a project as we could have ever taken on. We knew we would have some issues."
A small number of customers with automatic payment plans -- less than 1 percent of GM Financial's portfolio -- were either under- or overcharged on their payments this month. The average error was $20 above or below the customer's monthly payment, Beatty said.
"We take this very seriously. That's something obviously that a financial institution can't abide," Beatty said, adding: "Customers will be getting refunds of any overage that we withdrew from their accounts, and we'll work with customers on the ones where we withdrew too little."
On each due date this month, GM Financial found several hundred accounts that were affected. By the end of today, the last due date of January, GM Financial will have identified all affected customers, Beatty said.