Why does British Airways want to charge £652 for switching one domestic flight?

Many transatlantic flights overfly the Outer Hebrides; my British Airways flight last week from London to Denver did just that. But for the residents of Scotland’s wonderful Western Isles, reaching America proves a palaver.

Dolina MacLeod and her husband face a long journey in October when they travel from the Outer Hebrides to visit their daughter in New York. “We booked some time ago on British Airways from Edinburgh to New York via London Heathrow, both ways,” she says. “Since then, flight schedules have updated.”

Many people like to book flights months ahead. You have a fair chance of getting a better fare. But one downside is that airlines may tweak their schedules. A one-hour shift earlier or later is not much of a problem for straightforward point-to-point flights. But for connecting flights, it can mean an extended wait and a much longer journey overall.

“I enquired with British Airways to change the last leg of our journey – from Heathrow to Edinburgh – to an Inverness flight,” says Ms MacLeod. “This provides easier transportation links to return home to the Outer Hebrides.”

The extra distance is 112 miles. The extra cost? “I was incredibly shocked to be quoted £652 as the charge to make this change,” she says.

“I accept that there will always be amendment charges but the charges being quoted are more than the original fare for the entire trip from Edinburgh to NYC and back for one person.”

Ms MacLeod also spotted that the very Heathrow-Inverness flight she wished to fly on is being sold for just £56 one way, including a checked bag.

So how could this bizarre state of affairs come about: that so small an amendment could trigger such a surge in cost? And is there anything to stop the couple from simply buying London-Inverness tickets?

Let me explain.

Passengers rationally want to book at the lowest possible fare. Airlines are prepared to sell cheap tickets – but always with strings attached. If changes are permitted at all, they will come with an amendment fee plus any increase when the fare is recalculated.

Edinburgh-London-New York and back, booked months ahead, is a different beast from an outbound flight to JFK from the Scottish capital, but returning to Inverness, two months out. Computer doesn’t say “no”, but it does say “£652”. Unreasonable? It…