Heartland Payment Systems Inc. has introduced a system that lets its merchant clients reload consumers' prepaid phones using their payment terminals.

The Princeton, N.J., processor's ePIN It service, announced Thursday, gives owners of prepaid phones a personal identification number that Heartland's terminals print on a receipt. The consumers then give that number to their phone providers to add airtime minutes to their accounts.

William Collins, Heartland's senior director of vertical market strategy, said that the payment system will help retailers increase their revenue without having to stock any physical products on their shelves.

"Since this is a receipt-based service, merchants can increase their profits with each sale," he said in a press release. "Unlike traditional prepaid services that require merchants to purchase plastic cards and special terminals to process the transactions, there is no up-front investment."