A valid Polish passport or personal ID card are documents that confirm your Polish citizenship. If you do not have any documents to confirm your Polish citizenship or your personal data and citizenship cannot be determined, you can obtain confirmation of possession or loss of Polish citizenship.
My grandparents were Polish, can I confirm Polish citizenship?
If you can prove through documents that your ancestors had Polish citizenship and did not lose it during their stay in another country, it is possible to confirm your citizenship.
In addition to the documents of my ancestors, what personal documents should I present when applying for Polish citizenship?
You must present: identity document/passport, death, marriage and birth certificates, as appropriate, in order to prove the kinship link with your Polish ancestor.