Stay connected with AT&T in Mamaroneck. We offer phones, tablets, smartwatches, and connected devices from all of your favorite brands. We also offer wireless data plans in Mamaroneck for every need. Enjoy the flexibility of an Mamaroneck prepaid phone plan—with no annual contract and no credit check. Get unlimited text and data with AT&T UNLIMITED ELITE. Get nationwide AT&T 5G service, which comes with all of our unlimited data plans for no extra cost.