Before you start

An unlocked or eSIM-capable handset
Passport for SIM registration
PESEL, a Polish address and a bank account for a postpaid contract
Landlord or building administrator consent for a fixed-line installation

Step-by-step

1
Buy and register a prepaid SIM
Operator shops, kiosks and supermarkets all sell them, and registration against your passport happens at the counter. An unregistered SIM is deactivated within days.
In personWho: YouPLN 5–30 including starter credit
2
Use EU roaming while you decide
If you arrive from another EU country your existing SIM works at home rates under roam-like-at-home. There is no urgency and no reason to buy at the border.
OnlineWho: You
3
Lock your handset to Polish networks near the border
In the western districts and on the Berlin road, phones routinely register on German masts. Under EU rules that is charged at domestic rates, but it can still push you onto a fair-use cap on data, break location-based apps, and interrupt calls. Switching from automatic to manual network selection fixes it.
Mobile appWho: You
4
Ask the building, not the coverage map
In Pogodno, Łękno, Niebuszewo and the surviving prewar districts, ask the landlord or administrator which operators are physically wired into the building. A renovated villa may have fibre; the one next door may not.
In personWho: YouBefore signing a lease
5
Keep a mobile router as the fallback
5G coverage across Szczecin is good and unlimited-data plans are cheap. If your building turns out to be a copper one, a router on a mobile plan is a legitimate permanent answer rather than a stopgap.
OnlineWho: You

Documents you’ll need

Passport for SIM registration
PESEL and Polish bank account, for postpaid
Lease or written landlord consent, for a fixed-line installation
Proof of address, for some contracts

Things most newcomers don’t know

Your phone will roam onto German networks without leaving Poland.

The border is close enough to the built-up western districts that German masts are often the strongest signal. EU roam-like-at-home means you are not billed foreign rates, but roaming still counts against the fair-use data allowance on some plans, and it can make maps, delivery apps and two-factor SMS behave oddly. Manual network selection, set once, removes the whole class of problem.

Source: community-reported; EU roaming rules

There is no anonymous prepaid market in Poland — and Germany has its own rules.

Polish telecommunications law requires every SIM, prepaid included, to be registered to an identified person. Germany has an equivalent requirement. If you keep a German SIM for the cross-border half of your life, expect to register that one too, in person, with a passport.

Source: Polish telecommunications law

German mobile pricing makes a Polish SIM worth keeping even if you move across the border.

Polish unlimited or high-cap plans cost a fraction of German equivalents, and EU roaming rules let a Polish SIM work at domestic rates anywhere in the EU subject to fair-use limits. Many cross-border households run a Polish primary SIM and a cheap German one for local numbers, which is cheaper than the reverse.

Source: community-reported, consistent with EU price comparisons

Port the number from the new operator; never cancel the old contract first.

Polish number portability is quick and free, but it only works while the outgoing contract is live. Terminating first releases the number and it is no longer yours to move. Start the process at the new operator, who then handles the termination as part of the transfer.

Source: UKE — Office of Electronic Communications

Common mistakes to avoid

Leaving your handset on automatic network selection and burning your roaming fair-use cap at home.
Trusting a street-level coverage checker for a prewar villa or tenement.
Expecting to buy an unregistered prepaid SIM on either side of the border.
Cancelling an existing contract before starting the number port.
Signing a 24-month contract before you have PESEL and a Polish bank account.

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