Mobile company O2 Ireland had 1.63 million customers at the end of December, up 29,000 on the previous three months.
Average monthly revenue per user - a measure of how much it makes from each customer - was unchanged at €45. Service revenue fell 1.5% compared with the same period last year due to price regulation of its termination rates. Termination rates are charged by operators for use of their network.
O2 chief financial officer Paul Whelan said revenue had levelled out as the Irish mobile market had become extremely competitive.
O2 Ireland is now owned by Spain's Telefonica.
