Avoiding UK airport tax

Don’t fly in or out of airports in the United Kingdom. That’s the only way to avoid it

Air passenger duty is £78 on economy flights plus there are some user fees but this does not amount to several hundred dollars.

The easy way is to leave via Ireland but you need separate tickets or a layover greater than 24 hours.

Just like taxes imposed in the U.S., they are just something you have to pay. All countries and airports have taxes; it’s just the amount that differs. Be happy there’s no exit tax like some S. American countries charge. Believe it was Chile where the exit tax was about $130 per person.

Sorry Marco, but the UK/airline imposed taxes for my May 2019 British Airways flight totaled $463 per person. $219 for Government, authority and airport, while the British Airways fees and surcharges were $244.

Edited: call it what you want; tax, fee, duty, surcharge, but it still adds hundreds of additional dollars to the cost of a trip. Believe that’s what the OP was inferring. But I could be wrong.

I have seen several hundred dollars in fees when using frequent flyer miles on British Airways. Is this what you are referring to?
One strategy I have heard of is to start your journey out of the UK at an airport other than Heathrow.

Make your trip a multi-country trip. Fly transatlantically to the UK and depart to SFO from Amsterdam, Brussels, Düsseldorf or wherever. The airline taxes are trace compared with flying home from the UK. I flew very cheaply on one way tickets to both AMS and DUS from Heathrow a few years back.

What British Airways takes for itself is not a tax at all; it is part of the fare however it is represented.

Flying from the UK only the £78 is strictly a UK tax. Various US taxes/fees amount to around £29.20. Then there is the passenger charge levied by the airport; for example at Heathrow that would be £46.62, Manchester £20.60 and Gatwick £14.72, so there can be a big variation in this.

Leaving the USA for the UK all the taxes are US - around £23.60.

As Marco says, the £78 APD charge is the only tax that goes to the government.

However, there is a simpler way to avoid this tax in relation to Scotland and that is to depart home from Inverness, as this airport is exempt from APD. Note that APD is a departure tax, so one only needs to depart home from Inverness - you can still fly an open jaw into Glasgow, Edinburgh or any other airport.

This can be handy if heading to the Highlands anyway, but I'm not sure it's worth making a detour to save $100 if your planned itinerary doesn't really go near Inverness! Similarly, I don't think it's generally worth making a detour to Dusseldorf unless the saving is very big!

Of course the complexities (and smoke and mirrors!) involved in airline fares and pricing will often mean that even with this tax exemption the flight involving INV will still be more expensive than one to or from somewhere else!

I think the best advice is always to shop around and don't just assume on booking flights to EDI. Glasgow has direct flights to the US too and can sometimes be much cheaper - it is also a better access point for the W Highlands, Ayrshire golf etc. Although Aberdeen and Inverness don't have direct US services, they too are often better access points for many popular spots like Skye.

If flying in a class above economy then the standard APD is £172 and this is more worth avoiding by taking an initial separate flight. I know of people who have done this to Inverness, but the cheapest European airport varies through the years; once it was Lisbon, then Helsinki etc. Dublin used to be a good choice (especially if the pre-clearance helps you later) but it is more expensive to fly out of there it seems today.

Just looked on United. Here is what they charge for a cash purchased ticket, one way LHR to EWR:

U.S. APHIS User Fee $3.96
U.S. Customs User Fee $5.77
U.K. Passenger Service Charge $56.60
U.S. Immigration User Fee $7.00
U.K. Air Passenger Duty $208.80
U.S. Transportation Tax $18.60

Looks more than £78.

Thank you everyone for your advise. So many choices. Maybe I can get a good fare in January to help off set the extra charges.
Cheers

U.K. Air Passenger Duty $208.80
...
Looks more than £78.

This is would be the standard rate of APD of £172 on a premium cabin, not the reduced rate of £78 for economy, or more formally "the lowest class of travel available on the plane".