Vodafone Idea's mobile consumer base declined by around 3.63 crore to 33.63 crore in November, according to a source.
The telecom operator had reported an increase of 1.89 lakh mobile customers on its network in October.
"Vodafone Idea HLR (home location register) subscriber in October were 37,26,76,689. In November, it has come down to 33,63,57,324. There is a difference of 3,63,19,365 as per the company report submitted to Trai," the source told PTI.
However, Vodafone Idea declined to comment on this information.
The source said the company keeps deleting inactive subscribers and the reduction is the result of the same.
"The company has reduced time period of recording active subscriber from 120 days to 90 days. Had it been the same period, the reduced number would have come at the end of December," the source said.
Vodafone Idea and Bharti Airtel had raised call and data charges by up to 50 per cent from December 3 onwards.