Heathrow Airport reported record passenger traffic in the first half of 2025 and said it will submit its proposal for an extra runway by the end of this month.
The airport, where IAG's (LSE:IAG) British Airways is the largest tenant, welcomed 39.9 million passengers in the first six months of the year.
Strong demand for long-haul travel and larger aircraft boosted volumes, the airport said, adding that it remains on track to surpass 84 million passengers this year.
Revenue rose 1.9% to £1.7 billion, with increased retail and food sales also helping.
Adjusted EBITDA rose 0.8% to £959 million, though profit before tax declined 37% to £203 million as finance costs rose.
CEO Thomas Woldbye said: “We are delivering on our vision to become an extraordinary airport, fit for the future. We are welcoming record passenger numbers and improving the services that matter most.”
Heathrow said it was the most punctual major hub in Europe so far this year, with 98% of passengers clearing security in under five minutes and nearly all bags arriving with their owners.
The airport's new five-year investment plan, covering 2027 to 2031, is under review by the Civil Aviation Authority. It aims to improve customer service and support airline growth while keeping airport charges below levels seen a decade ago.
A separate proposal for long-term capacity expansion, principally from the addition of a third runway, will be submitted to the UK Government by 31 July, and if approved could be operational by 2035.