Who: The Advertising Standards Authority (ASA) and Trainline.com Ltd (Trainline)
Where: United Kingdom
When: 27 August 2025
Law stated as at: 19 September 2025
What happened:
Two ads for Trainline, promising that customers would not find cheaper train tickets elsewhere, were deemed to be misleading by the ASA.
As part of Trainline’s Best Price Guarantee campaign, an ad on a video-on-demand (VOD) service featured a robot on a fictional planet who stated that “you won’t find cheaper same-day tickets anywhere else, but if you do, they’ll refund the difference.” A similar ad was also broadcast on the radio. A complainant challenged whether these ads were misleading.
Price promise or lowest price claim?
Trainline said that its campaign was a price promise, rather than a lowest price guaranteed offer. It said that the wording of the claim made clear that although Trainline was confident in its prices, if consumers were able to find cheaper tickets, it would refund the difference.
However, the ASA considered that consumers would take “you won’t find cheaper same-day tickets anywhere else” as an absolute claim that Trainline offers the lowest price in the market and that there is no need to search elsewhere. That impression was reinforced in the VOD ad by the robot going to extraordinary lengths without finding cheaper tickets.
Substantiating lowest price claims
While rail ticket prices are set by train operators, with no ability for third party retailers, such as Trainline, to change the price, Trainline was confident that it offered the lowest prices for the period of the campaign as it did not charge booking fees for same-day tickets, meaning that its fares were at or below the price of train operators. It also pointed to its SplitSave technology which can generate cheaper end-to-end fares by splitting journeys. It therefore contended that, on routes where SplitSave was offered, tickets would be cheaper from Trainline than from train operating companies, the majority of whom did not offer split ticketing. Trainline was only aware of one other operator with a split ticketing feature (and that operator used Trainline’s technology).
While recognising that fares are set across providers and that Trainline not charging booking fees meant that those tickets were sold at the set price (and, on that narrow basis, could not be found cheaper elsewhere), the ASA found that the ads did not make this clear. Instead, the ads gave a misleading impression of the basis of its price promise and the value of the offer. The ASA also considered that consumers were likely to understand that Trainline was offering competitively priced tickets by monitoring its fares against those of its competitors. The ASA therefore expected Trainline to hold evidence to substantiate the claim that consumers could not “find cheaper same-day tickets anywhere else.”
The ASA also found that Trainline’s reliance on SplitSave to infer market‑wide cheapest pricing amounted to inadequate substantiation for the claims. The assumption that split ticketing would generally make Trainline cheaper did not amount to evidence of ongoing, systematic price-monitoring capable of supporting an absolute “won’t find cheaper” claim. Trainline said that its monitoring was automated and could not be evidenced, which the ASA considered insufficient.
Trainline also noted that few refunds were claimed under its Best Price Guarantee campaign. Trainline contended that this showed that they were cheaper than, or the same price as, their competitors, but the ASA considered that the ads’ absolute claims could have discouraged consumers from seeking cheaper tickets elsewhere, thereby reducing the number of refund claims. Further, Trainline accepted that it had issued some refunds, demonstrating that finding cheaper tickets was achievable in some circumstances.
The ASA concluded that, absent evidence of adequate price monitoring, the claims were not substantiated. While Trainline intended the claims to convey its confidence in its prices, the ASA found the claims would instead be understood as absolute, and thus were misleading.
Why this matters:
The ruling highlights the important distinction between a “lowest prices guaranteed” and a “lowest prices guarantee” claim. As the ASA’s guidance on this topic states, the former constitutes a claim that the product cannot be purchased for a lower price elsewhere (with the marketer having undertaken extensive monitoring and lowering its prices in response to market movements), while the latter is a price promise, where the advertiser promises to take action if a lower price can be found.
Advertisers should remember that offering a price promise does not justify an accompanying lowest price guaranteed claim if the lowest price claim cannot be substantiated. Absolute lowest price claims should be supported by ongoing, systematic price monitoring.
