Cellular 3 having been the first), used the O₂ network but operates separately. It has been allocated the area code 089. As with Tesco's mobile service of the United Kingdom, it is branded Tesco Mobile. The network commenced operation in 2007. Tesco Mobile had 375,000 customers in Ireland as of August 2017.

In March 2015, after it was announced that Three had purchased O2's Irish operations, it was announced that the O2 Ireland network would