Registration with the
Russia is a country that is bonkers about bureaucracy and there is nothing to do about it but to play the game and go along with it or face the consequences – usually a fine but in some rare cases even deportation.
If you intend to stay in Russia for more than 3 days you are required to get registered with the authorities. Hotels are obliged to automatically register you, however other forms of accommodations may or may not provide registration support and some even charge for the service.
A registration stamp is placed on the back of the immigration
must be handed back to the immigration control officer upon departure –
so keep it safe.