Possible Visa Problems
Provided you are registered promptly on arrival and leave Russia before your visa expires, you should have no problems with bureaucracy. Unless, of course, you are unfortunate enough to lose your passport or have it stolen during your trip. This is certainly a nuisance, and may be a severe interruption to your trip. Do not despair, however, the advice below will help you to minimize the difficulties involved, and ensure that you get home safely even if you have been foolish enough to flout Russian visa regulations. And do make copies of all your travel documents in case of emergency.
Lost or Stolen Passport and Visa
As nearly all Russian visas are now a sticker inside your passport, it's pretty much impossible to lose a visa on its own. If you do lose your passport during your stay in Russia, your first step should be to contact the nearest consular department for your country of origin. You will also have to go to a police station in order to obtain an official form confirming the loss or theft of your travel documents. We recommend, however, that you contact your embassy or consulate first, as they may be able to help non-Russian speakers with the necessary paperwork. If you don't speak Russian and have to contact the police yourself, you should call the 24-hour English-speaking operator at the St. Petersburg Bureau for Crimes Committed By and Against Foreigners on 278 3014.
Once you have a new passport, take it, along with your plane ticket (if you do not have a return ticket, you will have to buy one before you are issued a new visa) and the police form to the company that issued your visa support documents. If you have a copy of your lost visa, you should also provide it. If the agency refuses to help you (although it is their legal obligation to do so), then your consulate should tell you what to do.
Failure to Register
Since January 2007, it is the responsibility of the party who provides accommodation to foreign travelers to ensure that they are registered. Failure to do so will result in heavy fines for them, so if your invitation has been issued by friends, for example, your help is essential. While you can theoretically get through your stay unregistered and then leave the issuers of your visa support documents to clear up the mess, you will also have problems if you are ever stopped by the Russian Police, who have the right to perform random document checks on anyone they see fit to ask, and can also fine you - in theory repeatedly - for lack of valid registration. While you are not obliged by Russian law to carry proof of identity, the police are permitted to detain you at a police station until they can officially establish who you are.
Lost Migration Cards
Your Migration Card is the piece of paper that you have to fill in at passport control. Seemingly a needless formality, it is nonetheless an important document for the Russian authorities, and should be treated with care. If you try to leave Russia without a migration card, the chances are you will be fined between $50 and $100 dollars, delayed, and you may have trouble if you wish to make an application for another Russian visa in the future. We therefore recommend that you always carry good-quality photocopies of all your travel documents, including your Migration Card.
If you do lose your migration card, it will have to be reported to the local Office of the Federal Migration Service where your visa was registered. You can either do this yourself or, as is probably easier, demand that the company which issued your visa support documents and registered you originally does it on your behalf.
Overstaying your visa
Russian officials treat violations of visa regulations extremely seriously, and you should not assume that you will be allowed to leave Russia untroubled if you stay beyond the expiry date of your visa. While many countries operate a policy of only penalizing visa offenders when they make a repeat application for a new visa, in Russia this may be the least of your problems - in theory, you can be banned from applying for up to 5 years. If you have overstayed your visa, you will have to obtain a separate Exit Visa, issued by the Federal Migration Service and monitored by the FSB (what the KGB became after the collapse of the Soviet Union). Fines are between $90 and $300 dollars, and the process can take up to 10 days to complete, meaning that you will have to reorganize your travel arrangements.
If you have good reason to stay in Russia after your visa expires - in case of injury, for example - make sure that you contact the company which is providing you with visa support as soon as possible.