On 10th February 2003, the requirements for Migration cards came into force for the purposes of migration control into the territory of the Russian Federation. Every foreign citizen (except for the members of the diplomatic missions and international organisations) is required to fill in a migration card when entering Russia. You can view it here (Link)
You will be given a migration card by your carrier before you enter Russia, they are also available at the ports of entry. You should complete both parts (entry and exit) and hand this over to the passport control officer on entry.
Please keep it safe and hand it back again to the passport control officer at departure. If you lose your migratory card you should report this to the regional bodies of the Federal Migration Service (FMS) within three days.
Please note that your next entry into the Russian Federation may be restricted if you do not submit your migration card when leaving the country.
When you cross the border into Russia, for example by air from London into Moscow or overland by train from Helsinki into St Petersburg, then you will be given a migration card which you will need to complete. The card is in two parts, part “A” and “B”, and both parts need to be completed (in block capitals) before you go through passport control.
Part “A” of the card will be kept by passport control on entry and part “B” is returned to you with an entry stamp on it – do not lose this card and keep it with your passport at all times. When you leave Russia you need to present passport control with part “B” of your migration card containing your entry stamp and your registration slip, if applicable.
If you have failed to register your visa correctly or lost your migration card or registration slip, then you may have problems with passport control when leaving Russia including fines of up to $3000.