Updated on 12 November 2026 by Nicolas Finet, CEO of Sortlist. We have rewritten this guide for UK advertisers: what comparative advertising is, why brands use it, the UK rules that apply and a checklist for staying compliant. The earlier version gave general best practice without covering UK law, so we added the legal framework and shortened the rest.
Comparative advertising is advertising that compares your product, service or price with a competitor's, either by naming the competitor or by making the comparison identifiable. In the UK it is legal and often effective, but it is tightly regulated: comparisons must be accurate, verifiable, fair and not denigrate the competitor.
Key takeaways
- Comparative advertising is allowed in the UK if it is not misleading, compares like with like and rests on verifiable facts.
- Three instruments apply: the CAP Code, the Business Protection from Misleading Marketing Regulations 2008 and the Consumer Protection from Unfair Trading Regulations 2008.
- Do not denigrate or discredit a competitor, and do not use their trade marks in a way that misleads or takes unfair advantage.
- Keep evidence on file before the ad runs: the ASA expects substantiation, and awards or consumer opinion are not a substitute for objective proof.
- Use it to educate buyers and make a clear point of difference, not to attack.
Why use comparative advertising?
| Benefit | How it works |
|---|---|
| Stand out | Gives buyers a reason to choose you over a known alternative |
| Increase awareness | Associates a newer brand with an established one in the same category |
| Educate customers | Shows differences in price, features or performance in a way that helps decisions |
| Build social proof | Backs claims with tests, customer data or independent results |
The UK rules in brief
- Compare like with like. Under the CAP Code, comparisons with identifiable competitors must compare products that meet the same need or are intended for the same purpose.
- Verifiable information. Comparisons must be based on verifiable facts. You must hold documentary evidence, and consumer perception data or awards do not replace objective substantiation.
- No denigration. Marketing must not discredit or denigrate another product, marketer, trade mark or trade name.
- No confusion or unfair advantage. Do not create confusion between you and a competitor, or take unfair advantage of their reputation or trade mark.
- Price comparisons. Compare like with like and make clear what is compared and when prices were checked. The CAP Code was relaxed in 2013 so that price comparisons no longer require identical products, but the comparison must still be fair.
- Not misleading. The overall impression must be accurate, including what is omitted.
Rule numbers vary in how sources cite them (around 3.32 to 3.42 of the CAP Code), so check the current Code text on the ASA website. The ASA's own guidance is advisory and not legal advice.
Sortlist editorial note: before publishing, ask a colleague who has not seen the evidence to try to disprove the claim. If they can, the ASA or the competitor can too.
Sortlist editorial team
Best practices for a compliant comparative ad
- Stick to facts. Use measurable, current and relevant features, prices or test results.
- Choose a fair basis. Same specification, same time period and same conditions.
- Keep evidence. Store test methods, screenshots and dated price checks.
- Be careful with trade marks. Naming a competitor is generally allowed for comparison, but do not use logos or styling in a way that suggests affiliation.
- Do not bash. Make the point about your strengths and let the data speak.
- Use humour sparingly. Jokes about a competitor can read as denigration.
- Update regularly. Remove or revise claims when prices or products change.
- Get legal review. For named-competitor campaigns or sensitive sectors such as telecoms, finance and health, take advice.
Examples of acceptable and risky claims
| Claim type | Likely acceptable | Risky |
|---|---|---|
| Price | "Our basic plan is £10 a month cheaper than Brand X's equivalent plan (checked on 1 November 2026)" | "Cheapest in the UK" with no evidence |
| Performance | "In independent tests, charged 20% faster than Brand X Model 3 (test report available)" | "Brand X is useless" or comparisons with outdated models |
| Features | "Includes feature A, which Brand X does not offer" | Omitting that the competitor offers it on a higher plan |
| Satisfaction | "Rated 4.7 against 4.2 on [named review site], 2026" | Cherry-picked reviews or a small sample presented as general |
Consequences of breaking the rules
The ASA can order ads withdrawn and publish rulings that damage reputation. Competitors can also bring legal action, for example for trade mark infringement, malicious falsehood or breach of the 2008 Regulations. Regulators can pursue persistent offenders.
Frequently asked questions
Is comparative advertising legal in the UK?
Yes, if it is not misleading, compares comparable products, is verifiable and does not denigrate or confuse.
Can I name a competitor?
Yes, for a fair comparison, but do not use their trade mark to suggest a link or to take unfair advantage.
Do I need proof before running the ad?
Yes. You must be able to substantiate claims when the ad runs, not after a complaint.
Can I compare prices with a competitor?
Yes, with a fair like-for-like basis and clear dates and conditions.
Who regulates comparative advertising?
The ASA enforces the CAP Code; the 2008 Regulations are enforced through courts and public authorities.
Planning a comparison campaign? Post your project on Sortlist and compare UK advertising agencies for free.
Sources: ASA, a quick guide to comparative advertising, ASA, comparisons: general, RPC, CAP guide on comparative advertising campaigns, Sprintlaw, comparative advertising legal risks. Rule numbering differs between sources; this is general information, not legal advice.
