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 airport.
OnlineWho: You
3
Ask the building, not the coverage map
In Jeżyce, Wilda and Łazarz, ask the landlord or administrator which operators are wired into the stairwell. A renovated tenement often has full fibre; the one next door may have copper.
In personWho: YouBefore signing a lease
4
Order the installation early
Where fibre exists, installation runs one to three weeks and usually needs an engineer plus the administrator's permission for any new cabling. Start it the week you sign, not the week you move.
OnlineWho: You
5
Keep a mobile router as the fallback
5G coverage across Poznań is dense 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

Trade fair weeks are the one time Poznań's mobile network feels crowded.

The Poznań International Fair grounds sit in the middle of the city beside the main station, and the big events bring tens of thousands of visitors into a few hundred metres. During BUDMA, ITM and the larger consumer fairs, mobile data around Głogowska and the station genuinely degrades. If you work from a café in that area, know which weeks to avoid.

Source: community-reported

There is no anonymous prepaid market in Poland.

Polish telecommunications law requires every SIM, prepaid included, to be registered to an identified person. There is no way to buy one for cash without documents, and one sold without proper registration is deactivated. Bring a passport to the kiosk instead of expecting to sort it out later.

Source: Polish telecommunications law

Poznań's tenement districts survived the war, which is exactly why their internet is uneven.

Jeżyce, Łazarz and Wilda kept their nineteenth-century stock where much of central Poznań did not, and those buildings have been modernised piecemeal ever since. Two addresses on the same street can differ between symmetric fibre and ageing copper. Operator coverage checkers answer at street level and therefore answer the wrong question.

Source: community-reported

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