T-Mobile is the first wireless carrier to offer the Square credit card readerfrom San Francisco-based Square in its stores. The readers are already available at retailers such as Target, Best Buy and Apple stores, and T-Mobile has previously been selling the readers in 4G smartphone bundles for businesses, according to The Washington Post

T-Mobile says the reader will be a bonus for small businesses because it can make it easier and faster to get paid from shoppers using their credit cards. The Square reader lets small businesses take credit card payments using the mobile card reader attached to their iPhones, iPads or Android devices, with the money from the transaction sent for deposit into the bank account of the small business the next business day.