Can you name a competitor in your advertising?
Yes — comparative advertising is lawful in the UK and EU, and it is deliberately permitted because comparison helps consumers. But it is permitted only on strict conditions, and failing any one of them turns a comparison into both an advertising breach and potential trade mark infringement.
The conditions a comparison must satisfy:
It must not be misleading, in any respect.
It must compare goods meeting the same needs or intended for the same purpose — comparing unlike things is not permitted.
It must compare material, relevant, verifiable and representative features. "Verifiable" is the one that catches advertisers: the claim must be capable of being checked, which means the basis of comparison has to be substantiated and available.
It must not create confusion between you and the competitor.
It must not discredit or denigrate the competitor's marks, goods or activities. Robust comparison is fine; disparagement is not.
It must not take unfair advantage of the competitor's reputation.
It must not present goods as imitations or replicas of a protected brand.
Price comparisons must be genuine like-for-like, current, and clear about what is included.
On trade marks. Using a competitor's name is permitted within these conditions — this is the honest-use position. Step outside them and the protection falls away, exposing you to infringement claims, which is why the conditions matter commercially and not only for compliance.
What this means in practice:
Document everything before publishing. The evidence must exist at the time the claim is made, not be assembled after a challenge.
Date-stamp price comparisons and state the basis.
Beware "the UK's best" and similar superlatives — these are objective claims requiring proof, not opinion.
Competitors complain, and they are the most motivated complainants there are.
Brand bidding on a competitor's name in paid search is a related but separate question, governed by platform policy and trade mark law.
General information, not legal advice.