Tesco Mobile subscriber numbers increased by 25% in 2010 to reach 2.5 million subscribers.
Bumper Christmas sales are believed to have helped boost customer numbers to help Tesco reach this milestone on 25th December 2010.
As several thousand handsets were reported to have been activated on Christmas Day, while happy recipients opened their presents, activated their handsets, and used their newly gained mobile phones, Tesco Mobile were welcoming their own "Christmas Milestone".
Both Contract and Pay As You Go (sometimes referred to as "pre pay") customer bases grew during each quarter of 2010.
Post paid (contract) tariffs were introduced during 2010.
The growth was helped by the opening of Tesco Phone Shops across the country as well as new services and products.
Since the first Tesco Phone Shop was opened in Broadmead, Bristol, in November 2010, the number of Tesco Phone Shops now total almost 200.
It is reported that this growth in Tesco Mobile Subscribers is making Tesco Mobile one of the fastest growing Mobile Virtual Network Operators (MVNOs) in the United Kingdom.
Tesco Mobile operates over, and in partnership with, the O2 Network.