The author presents theoretical and practical problems that arose against the background of regulations governing voluntary pension, disability and sickness insurance and eventually led to amendment of the System Act by virtue of the Act of 24 June 2021 amending the Act on social insurance system and certain other acts (Journal of Laws 2021, item 1621). This article discusses the legal nature of the application for voluntary insurance coverage, the consequences of paying an incomplete contribution, as well as in what form the Social Insurance Institution's decision was and should be made after considering the application for consent to pay the contribution after the deadline. A new legal regulation is also presented which is to replace the current one and eliminate the difficulties related to the application of the previous regulations.