Bharti Airtel, India’s biggest mobile operator, lost 1 million subscribers in September 2012, as operators in the market continue to disconnect inactive users in a “clean-up drive”, Reuters said.

According to figures published by the Cellular Operators Association of India, Bharti’s base now stands at 185.9 million.

Airtel is not alone in pruning its customer base. Vodafone India lost 0.69 million customers in the month to stand at 152.7 million, while number-four Idea Cellular lost 0.51 million to stand at 115.5 million.

It had previously been reported that India’s operators had already disconnected more than 20 million customers, with Reliance Communications disconnecting a particularly large number of inactive prepaid users.

At this time, it was noted that the operators are complying with changed definitions of whether a subscriber is active or not.