TY JOUR TI Problems of regulation of the activities of registered entrepreneurs in the terms of application of the special tax regime “Tax on professional income” KW entrepreneurship KW professional income tax KW self-employed KW special tax regime KW taxes KW legislation KW Federal Tax Service JO The Economy under Guard AU Elfimov, O.M. AU Shchekaleva, K.S. PY 2022 IS 2022 PB Nizhny Novgorod Academy of the Ministry of the Interior of Russia