Telecom regulator TRAI has slashed the international incoming call termination rate to 30 paise, from 53 paise, to curb the "grey route", an official statement said.
The new rate will be effective from 1 February.
"The Authority has reduced the termination charges payable by an International Long Distance Operator (ILDO) to the access provider in whose network the call terminates from Rs 0.53 per minute to Rs 0.30 per minute," Trai said in a statement.
The telecom firms levy termination charge on operators from whose networks calls have been made, for transmitting them to the subscriber.
The Telecom Regulatory Authority of India said the new rule "shall come into force from the 1 February, 2018".
In a background note, it mentioned the existence of grey market which routes the ISD calls made to India by setting up illegal VoIP (voice over internet protocol) gateways which need to curbed.
TRAI said the menace of grey route poses serious security threat to the country apart from causing significant leakage in the revenue accruable to the country and its telecom service providers, and, proliferation of OTT (over-the-top) route for the carrying international voice traffic has many non-cost factors,
It said, "The Authority is of the view that, while deciding on the appropriate level of ITC (international termination charge) in the country, curbing the menace of the grey route should be a more important regulatory priority than facilitating the shift of the international incoming traffic from OTT route to carrier route."