Cabin baggage limits on flights are maddeningly complicated. Airlines come up with their own rules on the exact dimensions and weights of hand luggage. Some charge for anything more than a small backpack, laptop case or handbag – others don’t.

If you normally fly on airline X, don’t assume your bag will also be compliant on airline Y.

Many “legacy” carriers such as British Airways and North American airlines have a generous two-item allowance for cabin baggage. But budget airlines in Europe do not.

The only sure way to comply with all the leading carriers with no extra charge is to have one small bag no bigger than 33 x 25 x 15 cm.

Yet according to one of the many reports circulating on mainstream news sites online: “The European Union is poised to roll out a new set of rules aimed at making air travel more straightforward and less unpredictable. From 1 September, changes to hand luggage regulations will be implemented as part of an initiative to standardise the dimensions of carry-on bags”.

Travellers are told, incorrectly, that starting in September, passengers on EU airlines will be entitled to “one piece of hand luggage and one small personal item, such as a handbag, backpack, or laptop bag”.

The story is nonsense. It is not clear why there should be widespread reporting about something that is not happening. But these are the key questions and answers about what is happening, with sources for the information provided.

Is the EU is making it mandatory for airlines to give a generous cabin baggage allowance?

No. The European Commission told me: “There is no upcoming EU regulation which foresees changes to hand luggage rules.”

The European Parliament passed a resolution last October saying: “EU-wide harmonisation of the requirements on the size, weight and type of carry-on and check-in luggage for all airlines operating in the European Union would enhance transparency and consumer protection for all air travellers.”

Given the current confusion, airports, airlines and passengers would surely agree with that.

What is the EU actually doing, then?

According to the European Commission Department for Mobility and Transport, a workshop took place in July “with all interested stakeholders to discuss possible common industry standards on the weight and dimensions of hand luggage”.

A spokesperson told me: “The Commission expects to hear further details from industry on the progress towards common standards soon and plans to organise a follow-up workshop in autumn.”

So the airlines are signed up to this?

Yes. The trade association Airlines for Europe (A4E), representing British Airways, easyJet, Ryanair and the leading airlines from Continental Europe, is on the case.

Michael O’Leary, chief executive of Europe’s biggest budget carrier, Ryanair, told me: “We do think there should be a standardised agreement on what can be brought on board.

“We’re working with the other airlines in A4E to try to agree standardised sizes, but we haven’t reached an agreement with them yet.”

But doesn’t the EU want to abolish charges for cabin baggage?

Ideally, but then you get into the tangle of European institutions with their own views, and overlapping and conflicting spheres of influence.

The European Court of Justice decided a decade ago that hand baggage constitutes a “necessary aspect” of air travel and that passengers should be able to take a reasonable amount without paying extra.

The European Parliament wants a rule that people should be able to take a couple of pieces of hand luggage on board without being “subject to a price supplement”.

The European Commission says: “Member States are urged, therefore, to ensure that this ruling is respected, and, in the meantime, to strive for transparency with regard to the disclosure of any fees charged for carry-on luggage.”

Surely that means a generous free limit for everyone?

The budget airlines believe it can’t and won’t happen. Michael O’Leary of Ryanair says officials in Brussels “accept that there will have to be restrictions”.

He told The Independent daily travel podcast: “If you take our Boeing 737s [the only plane type Ryanair flies], we can only allow about half the passengers to bring a wheelie bag on board. There isn’t space on board the aircraft for any more bags.

“So we don’t think there’s going to be any legislation that will impose a right – or impose on all airlines, ‘You must take all these wheelie bags’ – because the aircraft won’t fit the bags.”

He would say that, wouldn’t he?

Yes, because budget airlines make a large slab of their revenue from charging for larger items of hand luggage. Low-cost carriers saying they make pricing entirely transparent. I have some sympathy with them. Yet one reason the European authorities are taking a closer look at the subject is because the airlines have brought extra attention to their policies by upping the cost of baggage to an absurd degree.

In September, for example, I can fly with Ryanair to Croatia from London Stansted for £15. But taking a larger piece of cabin baggage will cost an extra £23 – over 50 per cent higher than the basic air fare. That bears little relation to the marginal cost of someone taking their own hand luggage on board.

When will things change?

Who knows, but I do not expect any action before summer 2025. Uniformity will be particularly tricky for regional carriers with small aircraft.

For example, Loganair has maximum cabin baggage dimensions of 40cm x 35cm x 18cm because of the size constraints of its fleet. A case with those exact dimensions would have a volume of 25 litres, which is 60 per cent less than the limit for a large piece of hand luggage on British Airways.

Meanwhile, just ensure you comply with the rules for your airline.

Any idea why those online articles about free baggage started appearing?

My best guess is that perhaps editors conflated the return of the uniform 100ml rule on liquids in cabin baggage across Europe – which is definitely happening on 1 September 2024 – with the proposed changes to hand-luggage allowances outlined by the European Parliament.