Entry requirements for EU citizens:

The citizens of EU member state to enter Poland need only a valid travel document or a document confirming identity and citizenship (i.e. your national ID).

There are no formal requirements for a stay shorter than 3 months. However, after that period it is necessary to register your residence in the Voivodship Office:

Address:

Wielkopolska Voivodship Office
Plac Wolności 17, 61-739 Poznan, 4th floor
cudzoziemcy@poznan.uw.gov.pl