Citizenship of the European Union
In accordance with the official requirements of the Mazowieckie Voivodship Office (https://www.gov.pl/web/uw-mazowiecki/uznanie-za-obywatela-polskiego) in the case of recognizing a Polish citizen, you must submit a document confirming the legal title to occupy a dwelling , i.e. a rental agreement, an ownership deed or a lending agreement (in the case of a lending agreement, you also enclose a notarial deed regarding the rented premises; the lending agreement is concluded between ascendants, descendants, siblings).
Doubts are raised by the reservation that the lending agreement is concluded between ascendants, descendants and siblings. As you can guess, the Mazowieckie Voivodship Office wants to limit attempts to use false loan agreements. However, it should be noted that, according to the law, there is no limitation in concluding lending agreements. They can also be concluded between strangers. Therefore, the refusal to accept the application due to the submission of a loan agreement between third parties (treating it as formal defects of the application) has no legal basis.