Payment institutions and electronic money institutions are governed by the Law of 10 November 2009 on payment services ("the PSL"). The PSL was amended by the Law of 20 July 2018 which transposed Directive (EU) 2015/2366 of 25 November 2015 on payment services in the internal market (PSD2).

Payment services are defined in Article 1, point (38) of the PSL as "one or more business activities listed in the Annex, performed on a professional basis". Payment services are listed exhaustively in the Annex to the PSL.

Electronic money is defined in Article 1, point (29) of the PSL. It is "a monetary value represented by a claim on the issuer, which is (i) electronically, including magnetically, stored, and (ii) issued on receipt of funds for the purpose of making payment transactions, and (iii) accepted by a natural or legal person other than the electronic money issuer".