The CMA is cracking down on price transparency following the publication last year of the Digital Markets, Competition and Consumers Act.
In November, it launched eight formal investigations and issued more than 100 letters outlining concerns about unfair pricing practices and sales tactics.
These include misleading offers, extra charges and so-called "drip pricing", as well as firms designing customer journeys that pressurise consumers into acting quickly or spending more than they intended.
The holiday and package travel sector topped the list of the 14 types of businesses concerning the CMA, receiving 19 advisories, although no travel businesses were among the eight targeted by the CMA for formal investigation.
On Tuesday (17 February), Abta issued a reminder to agents that the guidance means pricing "must include unavoidable taxes and fees payable on arrival or departure at hotels, ports or airports".
"This applies to any business providing a price for travel arrangements to a consumer, including travel agents," Abta stressed.
The association has been liaising with CMA to make the authority aware that in most cases, agents will be selling products with prices set by a tour operator or supplier.
However, it said agents must nonetheless "do all they can to make sure the prices they are advertising or providing are total prices, including everything".
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Abta senior solicitor Paula Macfarlane said all travel companies should be aware of the CMA’s guidance.
"Although in relation to package holiday sales, the main responsibility will remain with tour operators to ensure they are compliant, agents should also take steps to ensure whatever they are offering to customers, the price includes unavoidable taxes and fees payable on arrival or departure at hotels, ports or airports."
Macfarlane added the CMA has issued guidance on how to include local taxes in adverts for accommodation-only bookings. Further information is also available from Abta's MemberZone.
Earlier this year, assessing the likely implications of the new legislation and the CMA's stance, Themis Advisory partner Jo Kolatsis said the messaging sent a clear message that any unavoidable charges must be part of headline pricing.
