Russian business visas allow for a single, double or multiple visits and may be valid from one to twelve months.
While tourist visa cannot be extended, business visa extensions can be arranged through the organisation which provided the invitation for the existing business visa.

Please note that a multiple entry visa is only available for people who have been issued a Russian visa before. A copy of your previous visa should be enclosed to your new application. If this visa was processed before 2013, we strongly recommend that you should contact your local Russian consulate and make sure that a multiple entry visa would still be available.

What are passport requirements for Russian visa? You have to submit your original passport with at least 2 blank visa-designated pages (passport must be valid for at least 6 months after intended departure date from Russia).

Foreign citizen minors must have a power-of-attorney, allowing them to travel if they are travelling alone or in the company of adults who are not their parents. Such miniors will be prevented from entering or leaving Russia if they cannot present such a power-of-attorney. In an effort to prevent international child abduction, many goverments have initiated special procedures at entry/exit points. These often include requiring documentary evidence of relationship and permission for the child's travel from the parent(s) or legal guardian if not present. Having such documentation on hand, even if not legally required, may facilitate entry/departure.