The MNP is a service that allows a mobile user to change his operator while retaining the number.
"There will be no further delay in the implementation of MNP," Telecom Regulatory Authority of India (TRAI) Chairman J.S. Sarma said.
"It has been decided that permission to launch commercial service in any area with effect from September 1, 2010 shall be given to only those licensee(s) who are MNP compliant," said a DoT note.
Mobile service providers - Bharti Airtel, Reliance, Vodafone Essar, Tata Tele, Idea, STel and Aircel - are ready to launch high-speed 3G services from next month.
State-owned telcos Bharat Sanchar Nagar Nigam and Mahanagar Telephone Nigam Limited have said full support will be given for the infrastructure to implement the MNP service.