The article examines theoretical and practical issues related to the establishment of the identity of citizens applying for notarial acts. The author analyzed the amendments and additions made to the norms of civil legislation regulating the procedure for establishing the identity of a citizen, including in the absence of a passport or other identity document, as well as the opinions of many representatives of the modern doctrine regarding the use of both traditional means of individualization of citizens and new ones based on the use of biometric technologies. Particular attention was paid to the problems arising in determining the gender of a citizen in some European countries, as well as the legal consequences of changing gender provided for by Russian legislation.