Before you start

An unlocked handset, or an eSIM-capable one
A US address for postpaid, but not for prepaid
A payment method — prepaid accepts foreign cards, postpaid usually does not

Step-by-step

1
Activate an eSIM before flying, or buy prepaid on arrival
A US eSIM activates before you land, so you have a working number for the taxi, the landlord and the bank. No identity registration is required at any point.
OnlineWho: YouDay 1
2
Check your handset is unlocked and band-compatible
Phones bought on contract abroad are frequently locked, and US band combinations trip up some regional models. With 3G shut down there is no fallback network.
OnlineWho: You
3
Start prepaid rather than fighting a credit check
Postpaid runs a credit check. With no US file you will be declined or asked for a deposit. Prepaid has no check and is usually cheaper for the same data.
OnlineWho: You
4
Leave Wireless Emergency Alerts on and add the county sheriff
WEA carries tornado and flash-flood warnings automatically. Snow emergency levels, which are legally binding at Level 3, are announced by each county sheriff's office rather than through WEA — follow the one for the county you commute into as well as the one you live in.
Mobile appWho: YouBefore November
5
Check coverage in the valley and the eastern hills
Cuyahoga Valley National Park and the Chagrin and Geauga uplands have real signal gaps. If you will be commuting through or hiking in them regularly, that is a better carrier test than the downtown speed figures.
OnlineWho: You
6
Port rather than cancel if you switch later
Number portability is a legal right and works between carriers and MVNOs. Request the port from the new carrier — never cancel the old service first, or the number is gone.
OnlineWho: You

Documents you’ll need

Passport for postpaid; nothing at all for prepaid
US address for postpaid
A payment card — prepaid usually accepts foreign cards, postpaid rarely does

Things most newcomers don’t know

Snow emergency levels do not come through the emergency alert system.

Level 1, 2 and 3 snow emergencies are declared by county sheriffs and published on their own channels, not pushed as Wireless Emergency Alerts. At Level 3 it is unlawful to be on that county's roads. Follow the sheriff's feed for both the county you live in and the one you work in, because they are frequently at different levels.

Source: community-reported

The US has no SIM registration at all.

Most countries in this app require passport registration to activate a SIM. The US requires nothing whatsoever for prepaid, so day-one connectivity is one of the easiest parts of arriving.

Source: community-reported

MVNOs are deprioritised during congestion.

MVNOs lease capacity from the major carriers and their traffic drops in priority when a tower is saturated — at a stadium, or during a weather event when everyone is calling at once. For everyday use they are fine and much cheaper; for a phone you rely on in a storm, the host carrier behaves better.

Source: community-reported

The credit check is the barrier, not the documentation.

Carriers check credit before offering postpaid, and a newcomer with no file gets declined or charged a deposit. Prepaid sidesteps it entirely and usually costs less for the same allowance.

Source: community-reported

Common mistakes to avoid

Assuming snow emergency levels will be pushed to your phone automatically — they are not.
Bringing a carrier-locked handset and discovering it on arrival.
Applying for postpaid with no credit file and facing a large deposit.
Choosing a carrier on downtown speed tests when your commute is through the eastern hills.
Cancelling the old carrier before requesting the port, and losing the number.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.