Russia’s four largest mobile operators will scrap domestic roaming fees in the next month, allowing Russian cellphone users to receive calls from other regions for the same price as local calls.

MTS, Megafon, Beeline and Tele2 have been under investigation by Russia’s anti-monopoly regulator, the Federal Anti-Monopoly Service (FAS), for levying roaming charges on incoming calls. FAS announced earlier this month that it had reached a deal with some of the operators to cancel domestic roaming fees.

Beeline kick-started the campaign to end roaming fees for incoming calls on Monday, when it announced in a news release that it was the first company canceling the charges.