Every Russian mobile number starts with 9. What the next three digits actually mean.
Structure
A Russian mobile number is +7, then a three-digit code starting with 9, then seven digits. The code is the allocation unit: the regulator assigns ranges of numbers inside it to operators.
One code, several operators
Old codes such as 903 or 916 are shared by several companies because the original holder sub-allocated ranges. Newer codes are usually held by one operator, which makes the answer unambiguous.
Codes are not regions
A mobile code does not define where the subscriber lives. Numbers are issued where the operator received the range, but the person can move anywhere. Only landline area codes (495, 812) are tied to a city.
How to read a code page
Each code page lists the operators and the number of ranges each holds. If one operator owns most ranges, the number most likely belongs to it. For an exact answer, check the full number.
Why new codes keep appearing
Capacity. When a code is fully allocated, the operator receives a new one — that is how 958, 977 and 999 appeared. They are not new companies.
See also: codes 958, 977, 999, identifying the operator.