AT&T is planning to test a fraud-detection service that will allow credit card companies to track the locations of customers who opt in.

The service is meant to provide more data to inform fraud decisions for purchases made during international travel. It will give card companies access to AT&T network data, allowing them to track customers' mobile devices to determine whether the cardholder is in the vicinity of a purchase being made with the issuer's card.

The service offers "an extra layer of credit card security," says Laura Merling, a vice president at AT&T, in a June 5 press release.

The new service uses an application program interface (API) to manage security preferences and provide companies with& location information. AT&T plans to pilot the program this summer, with the intention of launching it by the end of the year.