What is the dialing code from Russia to the UK?

The country code for the UK is +44, and then you must drop the leading '0' from the mobile number. For example, 07700 900123 becomes +44 7700 900123.

The plus sign means "insert your international access prefix here." The prefix from Russia is 8~10. Dial 8, wait for a second dial tone, then dial 10.

8~10 44 7700 900123

If you're programming the number into a mobile, enter it as +447700900123 (including the plus sign) and the mobile network will automatically substitute the appropriate prefix.