The Telecom Regulatory Authority of India (TRAI) also said telcos should alert users when they are on international roaming to deactivate internet if they don't want data services.
The Authority has released draft regulations related to data services and has sought comments of stakeholders. The final regulations are expected after May 12, the last date to submit comments.
TRAI said service providers should inform mobile subscribers, who have taken data packs, through SMS or USSD whenever the limit of data usage reaches 50 per cent, 90 per cent and 100 per cent.
It said when the usage reaches 90 per cent of the limit, information about the applicable tariff beyond the data limit shall also to be communicated.
TRAI said it has been receiving several complaints from consumers regarding non-availability of information relating to the amount of data used during a data session.