Presently, Mobile Number Portability is available only within the subscribers' service area.
When MNP is implemented fully, subscribers in Andhra Pradesh, for example, will be able to port their numbers to Karnataka, Maharashtra, Haryana and so on.
Earlier this year, Trai sought comments from stakeholders on the method that should be adopted to implement full MNP and the amendments required in existing regulations, among various other matters.
"After an examination of various issues, Trai on Wednesday released the recommendations on full MNP," the Authority said.
Telecom service providers will be given six month for the implementation of full MNP, it said.
The facility of pan-India portability will allow a mobile subscriber to change his licence service area (LSA) without having to change the number.
Trai said, "Implementation of full MNP would therefore mean acceptance of a porting request by the recipient operator from a mobile number belonging to any of the LSAs of the country, irrespective of the fact that the LSA from where the subscriber is porting his mobile number and the LSA to which he wants to port his number belong to the same or different MNP zones."