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 immediately. No identity registration is required at any point, for either option.
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 to land on.
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
Check the FCC broadband map before signing a lease
Albany's housing stock is largely brownstone and pre-war frame, and what is actually available on a given block depends on when that street was last built out. The FCC's national map reports at address level and is free. Ask the landlord what the previous tenant had, too — it is faster than any survey.
OnlineWho: YouBefore signing a lease
5
Leave weather and emergency alerts on through the winter
Wireless Emergency Alerts arrive on any US handset with no signup and carry winter storm warnings, flash flood warnings and evacuation notices. In a region where a lake-effect band or an ice storm can shut the Northway in an afternoon, that is the fastest warning available.
Mobile appWho: You
6
Assume no signal in the mountains
The Helderberg escarpment, the Catskills to the south and the Adirondacks to the north all lose coverage quickly, and the Adirondack Park in particular has enormous areas with none. Download offline maps, tell someone your route, and consider satellite SOS if you hike or ski alone.
Mobile appWho: You
7
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

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, which makes arriving with a working local number the easiest administrative task of the whole move.

Source: FCC — consumer guides on mobile service

Check the address, not the city, for broadband.

The FCC's map reports availability at address level. Albany's blocks were built and rebuilt across two centuries, and two flats in the same neighbourhood can have completely different options. This is the cheapest pre-lease check available and almost nobody does it.

Source: FCC — National Broadband Map

Winter alerts are worth more here than a weather app.

Wireless Emergency Alerts reach every handset with no signup and carry the warnings that actually change plans — ice storms, winter storm warnings, and the Northway closures that follow them. 511NY layers road conditions on top. Between them they are the difference between rescheduling a drive and being stuck on it.

Source: FCC — wireless emergency alerts

Coverage stops sooner than the mountains start.

The Helderbergs are twenty-five minutes from downtown and the Adirondack Park begins an hour north. Both lose service quickly, and the Park contains enormous areas with none at all. That is a real safety consideration in a region where winter hiking and backcountry skiing are ordinary weekend activities.

Source: National Weather Service — Albany forecast office