"The number of telephone subscribers in India increased from 964.20 million at the end of November, 2014 to 970.97 million at the end of December, 2014," the Telecom Regulatory Authority of India said in the report.
This surpasses the previous record of 965.5 million reached in June 2012.
Teledensity in the country, which means connections per 100, reached 77.58.
The mobile or wireless subscriber base in country is now already at all-time highs after it crossed 935.3-million mark at the end of October 2014. The previous record was set again in June 2012 when mobile subscriber base in the country reached 934 million.
At the end of of December, the total mobile subscriber base reached 943.9 million. Out of the total wireless subscriber base, 833 million wireless subscribers were found active in December, 2014.
In this record breaking journey, Bharti Airtel has maintained its leadership with 217.2 million mobile customers.
It is followed by Vodafone with 178.6 million mobile subscribers, Idea Cellular 150.5 million, Reliance Communications 106.2 million, BSNL 81.3 million, Aircel 78.6 million, Tata Teleservices 66.1 million and Uninor 43.6 million.
However, it is Idea Cellular that added over 2.5 million customers, the highest by any company, in December 2014.
It is followed by Airtel which added over 1.7 million new mobile customers, Vodafone about 1.5 million, Telewings (Uninor) 1.2 million, Aircel over 0.9 million, Tata Teleservices about 0.6 million, Videocon (including Quadrant) 0.27 million and MTNL 22,445 new mobile customers.
New operator Videocon registered the fastest growth rate in its mobile subscribers base and was followed by Telewings.
State-run BSNL in the reported month lost 1.3 million subscribers and Sistema Shyam lost 68,110 customers. Closure of Mumbai-based Loop Mobile business in November also brought down subscriber base by about 0.7 million.
During the reported month, about 3.5 million subscribers submitted request to change their mobile service provider taking the total number of such requests under Mobile Number Portability (MNP) service to 142.9 million.
The wireline connections further declined to 27 million from 27.1 million in November 2014.
The growth in broadband subscribers was also dominated by mobile operators with 69 million customers. The total broadband subscriber base increased by 4.28 percent on monthly basis to 85.7 million at the end of December from 82 million in November.