Comparative Advertising And English Law: Is Your Campaign Compliant?

Comparative advertising is a legitimate and widely used commercial tool. Telling customers your products or services are cheaper, faster, or better than a competitor’s is not unlawful, but only if you can back the claim up and stay within the rules.

When an advertisement draws unfavourable comparisons with a competitor, it engages specific legal obligations around misleading advertising. In the UK, those obligations are enforced by the Advertising Standards Authority. The ASA publishes its rulings, and its case history in this area offers a clear picture of where businesses most commonly go wrong.

The “identifiable competitor” threshold is lower than you might think

A common assumption is that leaving a competitor’s name out of an advertisement provides greater freedom. It does not. The ASA’s approach to what makes a competitor “identifiable” is deliberately broad: if a reasonable consumer could identify who the advertisement is aimed at, the stricter rules on comparative advertising apply.

Where no specific competitor can be identified, the rules are less strict, but they still apply. The comparison must be fair, the elements chosen to support it must not be cherry-picked to produce a misleading result, and any factual claims must be backed by evidence.

A 2014 ASA ruling illustrates this point clearly. An online retailer compared its prices with similar products sold on the high street, implying the saving was down to its direct-to-consumer model. The ASA expected to see evidence that the products were of equivalent quality, without it, the comparison was not a fair one. The advertiser could not provide that evidence, and the ad was found to be misleading. The lesson is a simple one: leaving out information that consumers would need to fairly assess a claim carries the same legal risk as making a false statement outright.

Price comparisons: the most common source of complaints

Price is the most frequently used basis for comparative advertising, and it generates the largest volume of complaints. Several rules are of particular practical significance.

The scope of the comparison must be made clear. In 2024, a major discount supermarket claimed to offer Britain’s cheapest Christmas dinner. The ASA found the ad misleading because the qualification, i.e., that the comparison was drawn from only seven supermarkets, appeared in print too small for most consumers to read. The headline said one thing; the evidence supported something narrower.

Transparency is required when comparing promotional prices against standard rates. A broadband provider claimed customers could save a substantial sum by switching from a competitor’s standard tariff. The competitor was, at the time, running a promotion, meaning the saving was not in practice available to new customers. The ASA found the advertisement to be misleading.

Savings figures must be genuinely representative. In 2025, a money transfer business displaying a “saved vs banks” figure alongside search results was found to have misled consumers. The figure derived from a limited sample of banks with significantly varying rates and fees, such that the saving available to any individual customer depended on their specific circumstances.

Comparisons against a recommended retail price carry equivalent risks. If the RRP used as a reference point is not the price at which the product is generally sold, the comparison is liable to mislead. An online wine retailer’s “prices you’re used to” comparison was found to be unsubstantiated in early 2025 on this basis.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.