You can use your mobile phone from home if your provider has a roaming agreement with a Russian mobile company. These are Russia’s top three nationwide mobile service providers:
To buy a SIM card, simply visit a provider’s retail outlet or an independent mobile phone dealer (e.g., Svyaznoy (Связной) or Euroset (Евросеть)). A passport and papers showing your local address and registration must be presented to sign up for service. We strongly advise against buying phones on the street or at flea markets.
During your time in Moscow, you can take advantage of several low-cost plans from the main mobile service providers. Typically, a monthly charge of 400 - 500 RUB will entitle you to 300-500 minutes of phone calls, unlimited SMS, and several GB of mobile internet (2G, 3G, or 4G).