The company also grew its margins by 9 per cent to £1.67 billion over the same period.
Its active customer base was up 3 per cent year-on-year at 10.6 million last year, while total contract customers rose 7 per cent YoY to 9.06 million as a result of increases in its B2B, 5G home and SMARTY base. The B2B customer base was up by 67 per cent YoY.
However, Three's operating expenses increased 23 per cent YoY to £1.02 billion due to increased network and IT running costs, greater site numbers and inflationary pressures.
Reported EBITDA was also down 34 per cent at £402 million, while it swung from a £147 million reported EBIT profit in 2022 to a £117 million loss in 2023, reflecting higher operating expenses, and an increase in depreciation and amortisation due to recent higher network investment.
Reported CAPEX declined 39 per cent YoY to £454 million.
Robert Finnegan, chief executive officer of Three UK, said, 2I am pleased to report another year of progress for Three UK. This year we have successfully increased our customer base, delivered topline revenue growth, and improved our margin. This was largely driven by the performance of certain segments such as SMARTY, 5G home broadband and B2B.
"But the cost of rolling out and maintaining our 5G network, and our commitment to improving connectivity across the UK, has impacted our profitability with negative reported EBIT for the first time since 2010.
"This financial performance is clearly unsustainable despite scaling back our 5G investment. With the current market structure of four MNOs, where there are two scaled players who have the ability to invest but do not face enough competitive pressure to do so, and two players (Three UK and Vodafone) who lack the scale to be credible challengers, the UK will continue to lag behind on 5G. The UK has the slowest data download speeds in the G7 and ranks 22nd out of 25 European countries in terms of 5G availability and download speeds.
"We are committed to improving our service for our customers and our country, creating additional jobs, and supporting the digital transformation that is taking place across the UK. The merger with Vodafone will enable the investment of £11 billion in the UK over 10 years to create one of Europe’s most advanced standalone 5G networks in full support of government targets."