day period, regardless of how long it is valid for (whether it be 3, 6, or 12 months). If you stay in Russia for 90 days, you have to leave and your visa will not permit you to return for another 90 days. This means (give or take - a year isn't 360 days) that a six month visa permits as long a total time in Russia as a three month visa!
Once you have your visa, check all the dates and information as it's much easier to correct mistakes before you travel than after you arrive!
Arrival and customs
On arriving in Russia, you'll have to fill out a landing card. As in most places, one half is surrendered on entry and the other portion should remain with your passport until you leave Russia. It is usually printed in both Russian and English though other languages may be available. Upon leaving Russia, a lost landing card may be overlooked with the help of a nominal fine.
Usually, you will be permitted to enter and remain in Russia for the term of your visa but it's up to the immigration officer to decide and they may decide otherwise, though this is unlikely.
Those who enter Russia with valuable electronic items or musical instruments (especially violins that look antique and expensive), antiques, large amounts of currency, or other such items are required to declare them on the customs entry card and must insist on having the card stamped by a customs officer upon arrival. Even if the customs officer claims that it is not necessary to declare such items, insist on a stamp on your declaration. Having this stamp may prevent considerable hassle (fines, confiscation) upon departure from Russia should the customs agent at departure decide that an item should have been declared upon entry.
Registration
Upon arrival to Russia and then subsequently upon arriving in any new city, you must be registered within 7 business days of arriving. Your host in that city (not necessarily the one who issued the invitation)
