Unlimited plan data cap of 40GB Tello Mobile and Ultra Mobile both leverage T-Mobile's vast and growing 5G and 4G LTE network to offer great coverage at lower rates. While Tello gives you the freedom to build your own plan, Ultra Mobile lets you save some extra money by signing up for a few months at a time. If you're looking for an affordable plan you can customize, look no further than Tello. If you're a heavy data user or want to have some extra international perks, Ultra Mobile is a better fit. Tello vs. Ultra Mobile: Same network, different plans