Apostille and legalization
Legalisation is the certification of a document’s formal conformity with the law binding in the place of its issue or of the authenticity of the seals and signatures placed on the document. In countries – parties to the Hague Convention of 5 October 1961 Abolishing the Requirement of Legalisation for Foreign Public Documents legalisation was replaced by apostille.
It is not obligatory to legalize your documents (or obtain an apostille) before taking them abroad.
Polish National Agency for Academic Exchange provides apostille and authentication on documents awarded by Polish higher education institutions. List of the documents is published in section “What documents we certify”