The operator also currently has 9.1 million active customers
Three saw its annual revenues for the whole of last year increase 4pc from £2.1 billion to £2.2 billion.
More than £1.5 billion came from customer service revenue, whilst handset revenue contributed £531 million.
The operator’s total registered customer base for the whole of 2016 also grew six per cent from 10 million to more than 11 million. Contract customers in the period grew from 6.1 million to 6.4 million, whilst prepay subscribers stood at 4.9 million.
Active customers stood at 9.1 million – an increase from 8.9 million the previous year. Over 6.3 million were on contract, whilst 2.8 million were prepay. Active contract churn decreased from 1.5 per cent to 1.4 per cent.
Additionally, Three claimed its customers used 6GB of data throughout December – five times more than the average consumer. Indoor coverage during that month also reach 95 per cent, up from 78 per cent in December 2011.
Three chief executive Dave Dyson said: “We’ve continued to make significant progress toward tackling the issues that frustrate and annoy mobile users in the UK.
“We look forward to the outcome of the next spectrum auction which will be vital in determining our ability to continue to challenge the market for the benefit of all UK consumers.”