From 1 March this year, Air Passenger Duty has been abolished for all children under the age of 16. It means anyone flying with kids after this date could be due a refund from their airline. The problem is that each airline is dealing with this differently - so yours may be hanging onto your cash.
The change was announced back in December 2014. In the first phase, the duty was removed for all under 12s from 1 May 2015, and travellers with younger children taking off after this date were forced to claim the tax back. Now a new tranche of families are affected.
This is essentially excellent news. As Hannah Maundrell, Editor in Chief of money.co.uk, points out: "This will save a family of four with two kids £26 on a flight to Europe and £142 on a flight to the USA."
However, there's a real risk that families will not get around to reclaiming their cash. A Money.co.uk survey showed that over a third of parents couldn't be bothered reclaiming the money, while those who said they were prepared to ask for their money back would only do so if they stood to gain an average of £28. Given that the average short haul flight to Europe comes with a £13 fee for air tax, this falls well short of the kind of money people would bother for.
How can you do it?
The first step is to check whether you have been charged the duty at all. The removal of the tax was initially announced at the end of 2014, so if you booked your ticket since then, there's a chance you haven't been charged duty anyway. However, don't assume this is the case, because a number of airlines have continued to charge it.
Most companies don't put the tax charge on their tickets, so you will need to call customer services to see if you paid the tax. You should also ask them for the procedure for applying for your money back. Money.co.uk has published a guide to how to apply for each - along with the relevant phone numbers.
Some are still charging the duty for those aged between 12 and 16, but are issuing automatic refunds if you're flying after 1 March. These include American Airlines, Delta Airlines and Thomas Cook.
Others have stopped charging the duty for this age group, but if you booked before they stopped, you'll get an automatic refund. These include easyJet, First Choice, Monarch and Thomson.
Others are still charging the duty, and insist you fill out a form to apply for your money back. These include Cathay Pacific. KLM, Lufthansa, Norwegian Air Shuttle (via the 'contact us' part of its website), Scandinavian Airlines, South African Airways, Swiss International, Virgin Atlantic and WowAir.
And then there are those who aren't charging for the duty any more, but if you booked before they stopped, you have to apply for a refund. These include Flybe and Ryanair.
Finally, there are those with more complex rules. British Airways is issuing automatic refunds if you booked after 30 September 2015. If you booked before then, you'll need to apply. Tickets booked very recently won't have charged the duty.
Jet2, meanwhile, asks you to log onto 'manage my booking' if you booked before December 2014, to request a refund. If you booked after this date, you'll get an automatic refund.
You also need to bear in mind that parents who booked package deals will have to go back to the tour operator to make a claim, not the airline.
Plus, if the total ticket price is less than the duty, you won't get a refund at all.
In future, there's always the hope that this tax will be scrapped for all passengers. This is something Flybe has been campaigning for. It says that the duty costs British passengers more than £3.1 billion a year - and has increased almost tenfold since 1995. It is the highest aviation tax in Europe and one of the highest in the world. It is particularly damaging for those flying within the UK - which it says is putting a brake on regional development.
We can only hope the government comes round to this way of thinking. In the interim, the very least we can do is make sure we reclaim every penny of the tax that we can.