Some disabled passengers are being charged double by airlines to fly from the UK, according to an investigation by the BBC.
Nearly 30 carriers contacted by the broadcaster said passengers with mobility problems must purchase a full-price ticket for a personal care assistant (PA).
This is despite Civil Aviation Authority guidance on EU law, maintained by the UK post-Brexit, urging airlines to subsidise the cost.
The European aviation regulations advise airlines to offer discounts for passengers who require an escort, but they are advisory only and cannot be enforced.
Disabled people with mobility issues say the situation is discriminatory.
BBC News said it contacted more than 100 airlines, including all that fly from Heathrow, to find out how many insist on a PA and whether they offer a discount.
Only Pakistan International Airlines was found to offer PA discounts for both international and domestic travel.
Some 28 airlines confirmed that they require passengers with mobility problems to purchase an additional PA ticket at full price – these include Emirates, Etihad Airways, American Airlines and Virgin Atlantic, as well as short-haul airlines such as EasyJet, Ryanair, Jet2 and Eurowings
A further 40 carriers, including Turkish Airlines and Delta, list either a recommendation or mandatory requirement to travel with a PA on their website, but do not clearly set out how much it costs, nor whether the individual or the airline should pay.
Some airlines in Australia, Malaysia, Canada and India offer concessions for domestic flights only, and Aegean said it examines requests on a case-by-case basis
The remaining 33 airlines either did not reply to the BBC’s request, had no information listed or stopped operating prior to publication.
BA told the BBC that it provided discounted PA fares on direct flights to Brazil and US, but declined to specify by how much.
US law allows for subsidised tickets, but only if the airline believes a PA is necessary for safety reasons and the individual does not.
When asked about the failure of airlines to adopt recommendations to subsidise PA fares, the Department for Transport said it was “committed to ensuring” accessible air travel but did not address the additional ticket charges.
However, the DfT said last month that it planned to give the CAA the power to fine airlines for breaching consumer laws.
This includes removing the reimbursement cap for damaged wheelchairs, which are currently treated like regular luggage and valued by weight, not price.
The CAA has also suggested a ranking to provide transparency about the disability performance of different airlines. A consultation period ended last week.
Airlines UK said carriers held a “proven track record” of constructive engagement on disability issues and would continue to be supportive of any initiative that improved quality and access to air travel.