How UK advertising rules limit best claims
UK advertising rules limit best claims on comparison pages: CAP 3.7 and 3.33 to 3.35 treat best, fastest and highest as objective claims that need evidence, a criterion, a comparison group and a date. ASA guidance also says an affiliate page must carry Ad before the click. This page explains the rules and what we changed because of them.
Re-check window: 90 days
What the rules ask for
The CAP Code is the rulebook the Advertising Standards Authority (ASA) applies to non-broadcast advertising. Our compliance notes tie the claims below to these rules.
- CAP 3.7. Objective claims need evidence. Best, fastest and highest are objective claims.
- CAP 3.33 to 3.35. Rules on comparisons, which apply when a page ranks one product against others.
- CAP 2.1 to 2.4. Advertising must be obviously identifiable, with a clear commercial purpose; advertorials need a clear label.
The wording of each rule is on the ASA's site. We summarise, and we do not quote beyond a short phrase.
What the ASA has said
| Source and date | What it says |
|---|---|
| ASA, Online Affiliate Marketing, 22 March 2023 | A page wholly about products with affiliate links should show Ad in the heading before the click. If only part of a page is affiliate content, Ad goes before the related content and links. Saying you may earn commission, or a footnote, is not enough. |
| ASA ruling, Optival Ltd, 28 October 2026 | Bonus advertising shown against a search about self-exclusion breached CAP 1.3. Negative keywords such as self-exclusion, Gamstop and problem gambling must be extremely robust. The affiliate received its own ruling. |
Sources: ASA affiliate marketing advice and ASA ruling on Optival Ltd.
How this site responds
- Criteria and dates. Where we use best, we name the criterion, the comparison group and the date. The main list, which UK-licensed casinos have the best live dealer blackjack tables, sets out how it was sorted. See also how we check operators.
- No scores. We give no ratings and no pass marks.
- Label above the content. A bar above every page shows Ad, 18+ and Gamble responsibly on pages with affiliate links. Pages without them say that no operator links are on the page.
- Disclosure. How the site earns money is on advertising and affiliate disclosure.
- Claims, checked. We test other people's best claims on claims checked, and are top casino lists paid for covers rankings.
The question of whether Ad is needed on every page, and our right to use best at all, are open legal questions that we have put to a lawyer before launch.
Quick answers
- Can a comparison page say best?
Only with evidence. Best, fastest and highest are objective claims, and CAP 3.7 and 3.33 to 3.35 call for proof, a stated criterion, a comparison group and a date.
- What does the ASA say about the Ad label?
In its affiliate marketing advice of 22 March 2023, the ASA says that if a page is wholly about products with affiliate links, Ad should appear in the heading before the click. Saying you may earn commission, or a footnote, is not enough.
- What did the ASA decide about Optival?
On 28 October 2026 the ASA ruled on Optival Ltd, an affiliate. Bonus advertising shown against a search about self-exclusion breached CAP 1.3, and the ruling says negative keywords must be extremely robust.
- Does this site call anything the best?
Only with a stated criterion, a comparison group and a date. The main ranking says how it was sorted and gives no scores.
- Who is responsible for an affiliate's advertising?
Both the business and the affiliate can be responsible, according to the ASA. The Optival ruling was addressed to an affiliate.