The requirements for documents needed at check-in depend on the type of accommodation and the applicable regulations. For hotels and other accommodation facilities, a Russian passport, an international passport, or a driver’s license may be accepted. For apartments, serviced apartments, and other properties where check-in or contract conclusion is carried out according to the rules of a specific property, the required documents are determined by the property itself. The day before arrival guests have to contact the apartment for check-in instructions and check-in time. Contact details can be found on the booking confirmation. Guests under the age of 21 are required to pay a deposit equal to 1 night's stay upon check-in.