Three national networks cover the US: Verizon, AT&T and T-Mobile, each with a genuinely different strength. Verizon has the longest-standing reputation for rural and remote reliability — deep in Montana, rural Appalachia, or long stretches of Midwest highway, Verizon is the network most travellers report holding a signal where others drop it. AT&T runs a close second on rural reach, particularly across the South, Texas and much of the interior. T-Mobile leads on urban and suburban 5G speed thanks to its mid-band spectrum, and its rural coverage has narrowed the gap significantly since acquiring Sprint's network, though the emptiest stretches of the country still favour Verizon or AT&T. A travel eSIM typically roams on one host network for the length of a trip rather than switching tower-by-tower between all three, so for most city-to-city and highway travel the difference rarely shows up; it matters most on long drives through the most sparsely populated interior states.
Device compatibility is worth a quick check before travelling: T-Mobile's rural reach depends heavily on its 600MHz low-band spectrum (band n71), while Verizon and AT&T's fastest 5G relies on C-band spectrum (band n77). Most unlocked phones from the past several years support the relevant bands for whichever network an eSIM connects to, but an older or previously carrier-locked device is worth confirming before departure. There is no equivalent registration paperwork to plan around: the US, alongside a handful of other countries including the UK and Mexico, does not require passport or ID registration to activate a prepaid SIM or eSIM at all.
Coverage in New York, Los Angeles, Chicago, San Francisco and Miami is strong across all three networks, with 5G widely available in downtown and suburban areas; the practical gaps for a visitor are more likely in national parks, mountain regions and the emptiest stretches of interstate highway than in any city.
The usual sequence still applies: install the eSIM profile over Wi-Fi before the flight, keep the home SIM active for calls and passcodes, and switch on the data eSIM once landed.