The new guidance, published last year, requires agents and other travel sellers to flag any mandatory taxes and charges payable on top of the price of a holiday upfront.

These could include resort fees, tourism taxes and city levies, which have become more common in recent years, particularly in historic destinations.

Power to bring enforcement action under the new guidance, enshrined in Digital Markets, Competition and Consumers Act, rests with the Competition and Markets Authority (CMA), which late last year issued more than 100 advisory letters after a review of more than 400 businesses and launched formal investigations into eight businesses.

Businesses in the "holidays" sector, which includes package travel, received the most advisories (19) of the 14 types of business of concern to the CMA, although none were singled out for investigation.

'Unavoidable charges must be part of headline pricing'

Speaking at the Advantage Travel Partnership conference on Wednesday (13 May), Travel Trade Consultancy Director Martin Alcock said agents could be forgiven for not having heard of the CMA, but warned it is now very much "on the scene and making noise". "They're definitely gunning for travel," he said.

"That DMCC piece of legislation, what it also did was give the CMA powers they've never had before to basically be judge and jury on deciding whether a breach has taken place, and deciding the fine," Alcock explained.

He highlighted the first case settled under the new powers, which saw the AA and British Driving School fined £4.2 million and ordered to pay back consumers £760,000 after failing to disclose a £3 transaction fee at the earliest opportunity.

"They've come out all guns blazing," said Alcock. "I think the scale [of the fine] is quite eye-watering. The consumer detriment, if you like, was about £750,000. But the fine was £4.2 million – and that was the reduced price, like when you pay a parking ticket early. So probably £6-7 million for a £750,000 deficit, it's mental."

Travel 'low-hanging fruit'

Jo Kolatsis, director of Themis Advisory, told delegates the pricing guidance applies at any initial "invitations to purchase". This, she said, in the case of agents, applies to prices featured in window cards, social media adverts and marketing offers.

Kolatsis said these prices had to factor in supply chain pricing, even if it's not paid to the agent or if it has to be paid by the client in destination. "The CMA has made it clear they will be looking for that," she added. "That's important because the travel industry is low-hanging fruit, unfortunately."

She advised: "Keep records of how you're pricing, who's taken a decision on pricing policy."

Alcock and Kolatsis agreed the CMA's intervention went hand-in-hand with a tougher line being taken by the Advertising Standards Authority with regards to travel, but advised agents not to panic if they receive an infringement notice, engage with the regulator at the earliest opportunity – and seek advice.

"Consumers are being wrapped in cotton wool more and more, and you have to keep on top of it," said Alcock.

Delegate Jackie Steadman, founder of TravelTime World, said social media posed a particular risk, with many agents copy and pasting offers from offers groups and pages.