Heathrow debt hits £17.6bn as airport records busiest year

Heathrow Airport has recorded its busiest year to date, welcoming 84.5 million passengers in 2025, even as its total debt rose to £17.6 billion.

The figures, released in Heathrow’s 2025 annual accounts today (25th February), have sparked a fresh row over the viability of the proposed third runway. While the airport says its performance ‘paves the way’ for expansion, campaigners have described the site as a ‘financial husk’.

Despite the £1 billion increase in debt since last year, Heathrow reported a revenue climb to £3.6 billion. Management highlighted the airport’s efficiency, noting it was crowned the ‘most punctual hub in Europe’ in 2025. Operational data showed that 97.3% of passengers waited less than five minutes for security, a factor Heathrow argues proves it is ready for further growth.

However, the No 3rd Runway Coalition argues that this ‘mountain of debt’ makes the projected £49 billion expansion cost a precarious gamble for the British economy. They point to a 37% drop in pre-tax profits—down to £575 million from £917 million the previous year—as a sign of underlying instability.

Paul McGuinness, Chair of the No 3rd Runway Coalition, issued a scathing assessment of the accounts, saying: ‘‘So, Heathrow remains a financial husk, with every asset mortgaged to the rafters for £17.6bn of debt and operating off an unsecured overdraft, rendering it technically bankrupt. And yet the government is backing its £49bn expansion. An inordinately expensive project which would cost a fraction of the price anywhere else in the UK, and absurd when the total cost of Gatwick’s expansion is just £2.2bn.’’

McGuinness further warned of the potential for a taxpayer-funded rescue: ‘‘Ratings agencies think it inconceivable that Heathrow could raise anywhere near even half the cost. And that a government which supports the project will be committing the taxpayer to bailing it out - if it’s ever to be more than an unfinished hole in the ground.’’

Heathrow remains steadfast in its expansion plans, announcing that shareholders recently approved new investment to begin the planning application process. The airport has also committed £1.3 billion for 2026 to revamp Terminal 4 and design a new baggage system for Terminal 2. Notably, the board decided to pay dividends totalling £550 million this year—the first such payment to shareholders in five years—citing a ‘strong financial position with liquidity of £2.9 billion’.

As Heathrow prepares to lobby for final approvals, the focus shifts to the Civil Aviation Authority (CAA). Regulators must now determine if the airport can afford its ambitious growth without passing excessive costs onto passengers. Heathrow expects a crucial parliamentary vote on the Airports National Policy Statement in the autumn of 2026.

Heathrow CEO Thomas Woldbye said: ‘‘Last year everyone at Heathrow rallied behind our ambition to deliver exceptional operational performance for our customers. Not only did we meet that goal, we surpassed it and achieved record‑breaking service levels. With strong foundations in place and with the airport now operating very close to capacity, the next chapter is crucial to our success. Expansion will unlock significant economic benefits and create an extraordinary airport, fit for the future. In 2026, we’ll continue progressing our plans so we can deliver for both our customers and for the country.’’