AT&T is now offering a $50 bill credit to customers who purchase a new iPhone from the Apple Online or Apple Retail Stores. Neither company has marketed the deal but an AT&T spokesperson confirmed the existence of the promotion to . The purchase and financing of any iPhone model that Apple sells, including the 5c, 5s, 6 and 6 Plus, qualifies the buyer for the credit. The $50 credit promotion, which runs through the end of the year, does have a number of requirements which should be easily met for most existing AT&T customers: - The iPhone must be purchased on an existing line as an upgrade. - The iPhone must be financed on an AT&T Next installment plan. - The iPhone must remain active and in good standing on Next for 45 days. Customers looking for an unlocked phone should wait for the bill credit to be applied to their account before paying off the AT&T Next financing and unlocking their phone through . The promotion launched earlier this week and is scheduled to run through December