The company, a joint venture between Britain's Vodafone Group and billionaire Kumar Mangalam Birla's Idea Cellular, also reported a bigger quarterly loss, as it set aside 194.41 billion rupees for dues owed to the government.
Late last year the country's top court ordered Indian telecom companies to pay 920 billion rupees in overdue levies and interest to the government.
It was "a challenging quarter as availability of recharges due to store closures and ability of customers to recharge on account of economic slowdown were impacted," Chief Executive Officer Ravinder Takkar said.
Vodafone Idea's subscriber base declined to 279.8 million users in the reported quarter, from 291.1 million users in the fourth quarter. Average revenue per user fell to 114 rupees from 121 rupees in the sequentially previous quarter.
The company, India's third largest telecom operator by subscribers reported its eighth consecutive quarterly loss of 254.6 billion rupees, compared with a loss of 48.74 billion rupees a year earlier.
Vodafone Idea's consolidated revenue from operations fell to 106.59 billion rupees during the quarter, compared with 112.70 billion rupees a year earlier.
(Reporting by Philip George in Bengaluru; Editing by Shinjini Ganguli and Shounak Dasgupta)