The Advertising Standards Authority (ASA) reviewed 362,000 unique paid-for online ads from "major UK travel agents" between August 2024 and June 2025, and found just 319 – less than 1% – included any environmental claims.
However, of those 319 ads, the ASA found that 213 of them from 23 advertisers – 67% – were likely to be non-compliant with its standards and guidance on how sustainability claims can be made, typically due to the use of "vague, unqualified or absolute terms".
Common compliance issues included making absolute claims such as stating a trip, product or service is "eco-friendly" or "green", or failing to adequately qualify claims or provide sufficient context.
Other issues highlighted by the ASA included firms making comparative claims such as "a greener way to travel" or "less carbon than flying", failing to substantiate claims made in product names or categories like "eco-resort" or "eco-lodge", or using broad claims like "carbon conscious".
It also highlighted problematic sector-specific issues such as cruise lines' sustainability claims relating to their use of alternative fuels like liquefied natural gas (LNG).
The ASA's ongoing AI-based monitoring aims to measure compliance, highlight good practice and identify emerging risks. The latest intervention assessed how well these ads, which appeared across social media, in paid search results and in paid ads on websites, stuck to advertising rules on environmental claims.
"With people increasingly focused on how environmentally friendly the products or services they're buying are, ensuring sustainability claims are clear and accurate is essential to ensure people are not misled – especially in higher emission sectors like travel," said the ASA.
"Informative and accurate environmental claims help consumers make better, more responsible choices. They also highlight the steps organisations are taking to reduce their impact, an important part of moving toward a low-carbon future."
The ASA added that with very few travel agents currently making environmental claims in their ads, it suggested either they are missing an opportunity to detail their green credentials, or are uncertain about how to go about making such claims in a compliant way.
"Many businesses are taking steps to reduce their environmental impact and want to tell customers about that," the ASA continued. "Our role is to help them do that in a way that is clear, accurate and supported by evidence."
It is encouraging firms to consult its online guidance, advice and training, and to seek out the sector-specific advice for travel on the ASA website.
