The requirement
A foreigner applying for recognition as a Polish citizen must have knowledge of Polish confirmed by one of these documents (Art. 30 para. 2 of the Act on Polish Citizenship):
- an official certificate of proficiency in Polish as a foreign language at level B1 or higher, i.e. the state certificate (Art. 11a of the Polish Language Act),
- a certificate of completion of a school in Poland,
- a certificate of completion of a school abroad with Polish as the language of instruction.
A certificate of completion of a post-secondary school does not confirm knowledge of the language for citizenship (Art. 30 para. 2a).
The requirement does not apply to children recognised under Art. 30 para. 1 points 4 and 5 - when one parent is a Polish citizen or has had citizenship restored. See: citizenship of a child.
The state certificate
The certificate is issued by the State Commission for the Certification of Proficiency in Polish as a Foreign Language after passing an exam (Art. 11a paras. 1 and 2 of the Polish Language Act). Exams are organised by entities authorised by the minister of science; their list and dates are published in the minister's Public Information Bulletin (Art. 11b para. 4).
A graduate of studies taught in Polish at a Polish university or of certain schools with Polish can get the certificate without an exam - on an application submitted through the Polish National Agency for Academic Exchange (Art. 11a para. 4 and Art. 11aa). A graduate of studies then gets a certificate at least at level B2 (Art. 11a para. 7).
Different documents than for EU resident status
For the EU resident permit, ECL and TELC certificates or a university certificate are also enough. The Act does not list them for citizenship. Compare: Polish at B1 for EU resident status.