Note: This advice is given by the CAP Executive about non-broadcast advertising. It does not constitute legal advice. It does not bind CAP, CAP advisory panels or the Advertising Standards Authority.

Superlative claims are those which claim that something is superior to all others, whether it is a broad claim, such as “the best” or a specific claim, such as “the most customers” or “the highest rated”.

The ASA will consider unqualified superlative claims as comparative claims against all competing products, and the rules on making comparisons with identifiable competitors will apply (Code rules 3.33 – 3.40). See Comparisons: general.

The CAP Code requires advertisers to hold documentary evidence to substantiate claims that consumers are likely to regard as objective and that are capable of objective substantiation. Superiority claims must be supported by evidence unless they are obvious exaggerations (puffery) or claims that consumers are unlikely to take literally.

Some claims may be understood by the average consumer as an obvious exaggeration. Claims which consumers are unlikely to take literally are allowed provided they do not materially mislead (3.2). Marketing communications must not imply that expressions of opinion are objective claims (3.6). See Matters of opinion and Types of claims: Puffery.



Puffery and obvious exaggerations


As with all comparisons, superlative claims must be presented in a way which is unlikely to mislead. The CAP Code requires advertisers to hold documentary evidence to substantiate claims that consumers are likely to regard as objective and that are capable of objective substantiation. See also Comparisons: Identifiable competitors and Comparisons: General.

The likely interpretation of an unqualified superlative claim will depend on the product or service advertised and the context in which the claim appears. The nature of the evidence required to substantiate superlative claims will depend on how it is likely to be understood by its audience. 

Unless the nature of the product or the context in which the claim appears gives the claim another meaning, or the meaning is ambiguous, “no. 1”, “best-selling”, “leading” and other similar claims are generally treated as objective best-selling claims. Claims which will be understood to be best-selling claims are likely to require evidence of highest sales or highest market share. An ad which made the claims “the leading trademark registration service” was ruled misleading by the ASA, who considered that consumers would understand the claims to mean that the advertiser had registered more trademarks than any other business. Because the advertisers did not have evidence to demonstrate that this was the case, complaints about the ad were upheld (Trademark Eagle Ltd, 21 February 2018). The ASA has also upheld a complaint about the claim “#1 holiday website on the planet”, because the advertiser did not provide evidence to demonstrate that the it had the largest turnover of holiday rentals when compared to their global competitors (Rental Republic Ltd, 19 January 2022). See also (Ryanair Ltd, 7 February 2018).

When making “best” claims, advertisers must consider consumers’ likely understanding of the claim. In 2018 the ASA upheld a complaint about an ad which stated that the advertiser’s mobile phones were the “best value”. The ASA considered that consumers would interpret the claim “The UK’s best value mobile” to relate to the features integral to the nature of a mobile phone service: minutes, texts and data, and because the advertiser did not offer more data, minutes and texts than all other UK mobile tariffs relative to the costs of the tariffs, found the claim misleading (Utility Warehouse Ltd, 08 August 2018). The ASA has also considered “best price” (The Carphone Warehouse Ltd, 03 August 2016), “best available tickets” (Ticketmaster UK Ltd, 03 January 2018) and “The Best Alarm Technology on the Market” (Verisure Services (UK) Ltd, 01 June 2022) misleading in the absence of evidence to support the claims.

Self-reported consumer data will not be sufficient to support a claim that would otherwise require objective substantiation. Marketers should not rely on consumer perception data, or the fact that they have recieved awards, to support claims for which they do not hold objective substantiation (Hutchison 3G UK Ltd t/a 3, 24 February 2021). For further advice see Comparisons based on awards and surveys.

For advice on specific types of claims see Types of claims: Best, Types of claims: Best-selling, Types of claims: No.1, Types of claims: Leading and Types of claims: Premier.


When making comparisons with identifiable competitors, as well as holding evidence to substantiate any claims, advertisers must ensure that their meaning is clear, they compare products or services intended for the same purpose, and are verifiable (3.33 – 3.40). For detailed guidance on these requirements see Comparisons: Identifiable competitors and Comparisons: Verifiability.

Because objective superlative claims are, by their nature, comparisons with all competitors, they are likely to be considered comparisons with identifiable competitors and must be verifiable.

To make a claim verifiable, the advertiser should set out the relevant information in the ad or signpost how the information used to make that comparison can be checked by the audience. The information required to make a claim verifiable will depend entirely on the specific comparison and the evidence used to support it. Generally speaking, marketers should include, or direct consumers to, sufficient objective information and data to ensure that consumers are able to check the claims are accurate for themselves (see Vodafone Ltd, 28 July 2021).

If verifying the comparison requires specialist knowledge, consumers should be able to get a knowledgeable and independent person or organisation to verify the comparison for them. Providing incomplete or inaccessible information, for example, behind a paywall, is unlikely to be considered sufficient (Procter & Gamble UK, 27 May 2020).

Puffery and obvious exaggerations

Code rule 3.2 states that obvious exaggerations ("puffery") and claims that the average consumer who sees the marketing communication is unlikely to take literally are allowed provided they do not materially mislead.

If the basis of a superlative claim is unstated, and is unlikely, in the context in which it appears, to have an objective meaning to consumers, the ASA may regard the claim as subjective. In 2020 The ASA considered that the claim “THE ORIGINAL AND THE BEST SINCE 2004”, in an ad for a pillowcase would be understood as a subjective expression of Slipsilk’s opinion about their product and was therefore not capable of objective substantiation (Slip Enterprises Pty Ltd t/a Slipsilk 11 March 2020). See also "to achieve the unachievable" and "Comfort redefined"(Alcon Eye Care UK Ltd, 4 September 2013).

Marketers should be cautious when using subjective claims or stating matters of opinion and should ensure that these will not mislead; marketing communications must not imply that expressions of opinion are objective claims (Code rule 3.6).

See Matters of opinion and Types of claims: unsubstantiable or puffery.

For sector specific advice see Comparisons: Telecoms and Comparisons: Travel

More on