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
The exact street address before you commit to a broadband plan

Step-by-step

1
Activate a US eSIM before you fly, or buy prepaid on landing
An eSIM bought before departure means you land with a working US number, which matters because banks, the DMV and rental applications all send SMS codes. No identity registration is required at any point in the US.
Mobile appWho: YouDay 1
2
Check your handset is unlocked and band-compatible
Handsets bought on contract abroad are frequently carrier-locked, and some regional models miss US band combinations. With 3G shut down there is no fallback network. Run your exact model through the carrier's compatibility tool.
OnlineWho: You
3
Start prepaid rather than fighting a credit check
Postpaid runs a credit check and a newcomer with no file is declined or asked for a deposit of several hundred dollars. Prepaid has no check, no contract and is usually cheaper for the same data on the same towers.
OnlineWho: You
4
Check broadband by address before you sign a lease
Run the exact street address through the FCC's National Broadband Map and confirm with the provider. Madison is better served than most Midwestern cities of its size and there are addresses with two or three real options — but the isthmus's older housing stock and the newer western subdivisions are very different propositions. For anyone working from home this is a lease-level question.
OnlineWho: YouBefore signing
5
Ask a landlord whether the building has a bulk internet contract
Many of Madison's larger and newer buildings, particularly the student-oriented ones near campus, sign a single provider deal bundled into the rent. That can be excellent value or it can lock you out of the faster option next door. Ask which provider, at what speed, and whether you may install an alternative.
In personWho: You
6
Leave emergency alerts on through the winter and the spring
Federal Wireless Emergency Alerts carry winter storm, blizzard and tornado warnings for Dane County — southern Wisconsin does get severe convective weather from spring into summer, and the winter storms are the more frequent disruption. Dane County also runs its own emergency notification sign-up. Set both up in your first month rather than during your first ice storm.
Mobile appWho: You

Documents you’ll need

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

Things most newcomers don’t know

The US has no SIM registration of any kind.

Most countries in this app require passport registration to activate a SIM and several require biometrics. The US requires nothing at all for prepaid — you can buy one with cash and never give a name. Arriving from India, Nigeria or the Gulf, the total absence of paperwork reads like an oversight. It is deliberate.

Source: community-reported

'Available in Madison' and 'available at 812 Williamson Street' are different claims.

Providers advertise at city level and build street by street. Madison's isthmus is a mixture of pre-war houses subdivided into flats and newer infill; two addresses a block apart can have entirely different options. Check the FCC National Broadband Map for the exact address and then confirm with the provider before you sign a lease you intend to work from — the map is the honest starting point, not the last word.

Source: FCC — National Broadband Map

The credit check is the barrier to postpaid, not the paperwork.

Carriers screen credit before offering a postpaid plan, and a newcomer with no file is declined or charged a deposit of a few hundred dollars. Nobody at the counter explains that prepaid avoids the check entirely, runs on the same towers, costs less, and converts to postpaid later once you have history.

Source: community-reported

Your number is portable, which makes the cheap-first strategy work.

Federal rules require carriers to release your number to a competitor, and you keep it moving prepaid to postpaid or back. That is what makes the sensible sequence possible — a cheap prepaid line for six months while you build credit, then a postpaid plan — without re-giving a new number to every bank, employer and landlord that already has one on file.

Source: FCC — porting your phone number

Common mistakes to avoid

Signing a work-from-home lease without checking what broadband reaches that specific address.
Accepting a building's bulk internet deal without asking the speed or whether you may install an alternative.
Bringing a carrier-locked handset and discovering it after landing.
Switching off Wireless Emergency Alerts and missing a blizzard or tornado warning.
Relying on a foreign number for bank and DMV SMS verification.

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