Why Heathrow has no Terminal 1

Look up Heathrow on our airports page and you will find four terminals: 2, 3, 4 and 5.

Not 1. That is not a gap in our data. Heathrow genuinely has no Terminal 1, and has not had one for over a decade.

It closed in 2015

Terminal 1 shut to passengers on Monday 29 June 2015. The last departure was a British Airways flight to Hanover, leaving that evening, according to Heathrow's own announcement.

It had opened in April 1969, and was opened by Queen Elizabeth II. At full capacity it handled around nine million passengers a year — a figure that sounds substantial until you set it against the eighty-odd million Heathrow now moves through the airport as a whole.

By the end it was running a fraction of what it was built for. British Airways was operating a handful of daily flights from it to a short list of European destinations, in a building designed for a different era of air travel.

It closed so Terminal 2 could grow

This is the part that explains the numbering.

Terminal 1 was not closed because Heathrow needed one fewer terminal. It was closed because it stood on the land Terminal 2 needed. The Queen's Terminal — Terminal 2 as it reopened in 2014 — was built in phases, and the later phase required the Terminal 1 site.

So the airlines and staff moved next door, the building came down, and the space became part of the terminal beside it.

Why nobody renumbered anything

Renaming Terminal 2 to Terminal 1 would have been tidier and considerably more expensive than leaving it alone.

Every sign on every approach road, every rail and Underground announcement, every airline booking system, every printed boarding pass, every piece of wayfinding inside the airport, and every taxi driver's habit refers to terminals by number. Changing three of those numbers to close a gap in a sequence buys nothing a passenger can use, and risks sending people to the wrong building for years afterwards.

Airports carry these scars. Gatwick has a North and South rather than numbers. Schiphol runs one terminal split into three departure halls. The naming reflects how each airport grew, not a plan drawn up in advance.

What this means when you fly

If a booking, an old guidebook or a relative's memory sends you to Heathrow Terminal 1, you want Terminal 2. That is where its airlines went.

And if you are checking a terminal before you travel, check it against the airport rather than against something printed earlier. Terminal assignments move — that is why every terminal on our airport pages carries the source it was verified against and the date we last checked it.