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.
The ASA and CAP recognise that comparisons help give customers valuable information as well as encourage competition between advertisers. But, as with all ads, it is important that they are clear and easy for consumers to understand and they comply with the relevant legislation.
The CAP Code requires that comparisons with identifiable competitor products “must objectively compare one or more material, relevant, verifiable and representative feature of those products” (rule 3.35).
For general advice on making comparisons with identifiable competitors see Comparisons: Identifiable competitors.
What is meant by verifiable?
What kind of comparisons require verification information?
What information is needed to make a claim verifiable?
Where, and how, should I provide the verification information?
What about surveys and test results?
What if my comparison is based on confidential information?
What is meant by verifiable?
The Code does not specify what constitutes ‘verifiable’, but in 2006 the European Court of Justice ruled, in the case of Lidl v Colruyt, that for a general price comparison to be 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 target audience.
While CAP does not give legal advice, the ASA has taken this position into account when investigating complaints on this issue.
What kind of comparisons require verification information?
Any comparisons made with identifiable competitors must be verifiable. Marketers do not need to explicitly identify the competitor(s) or product(s) that they are comparing with to be subject to the rules on comparisons with 'identifiable' competitors. If a consumer can identify at least one competitor or competitor product, whether they are stated in the ad or not, this will mean that the comparative claims must be verifiable. For more information, see Comparisons: Identifiable competitors.
Some comparisons are easily verifiable; a price comparison between two identical products sold by two different retailers, for example, could be checked by looking on their websites. Other comparisons, such as those that involve many products, are likely to be more difficult to verify, and the ad will need to provide sufficient information to allow consumers to verify the claim.
One advertiser questioned whether their ads were subject to the verifiability requirement, given they detailed a price match scheme, rather than a price comparison. The ASA ruled that because the competitors were identifiable, the verifiability requirement applied, and therefore the advertiser should have signposted consumers to the relevant information (Wm Morrison Supermarkets plc, 26 August 2015).
What information is needed to make a claim verifiable?
The information needed to make a comparison verifiable will depend on the specific comparison. Broadly, ads should include as much information as possible to ensure that consumers are able to check the accuracy of the claim for themselves, and include a signpost in the ad to information about the basis of the comparison. 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.
There are numerous examples of the ASA finding a complete lack of verifiable information. For example, RoofSURE’s claim that their insulation was ‘THE MOST EFFICIENT…ON THE MARKET TODAY’ did not include any information to ensure the details of the identifiable comparison could be verified by consumers and competitors. Nor did it direct them to where such information could be obtained (RoofSURE Ltd, 19 April 2023). Similarly, Uber’s claim that various benefits were only available to their drivers, and not drivers of their competitor, did not include (or signpost to) any information verifying that the benefits were provided by them alone (Uber BV, 5 April 2023). See also WaterWipes UC, 8 March 2023 and HomePPL Ltd, 15 February 2023.
The information that is provided must be sufficient for consumers to be able to verify the comparison. Simply citing a third-party website, such as MySupermarket.com in the case of price comparisons, without telling consumers which specific products were used in the comparison and the date the comparison was made, is unlikely to be acceptable.
The ASA has ruled on the inadequacy of verification information on multiple occasions. The information provided to verify Aldi’s claim to be ‘THE HOME OF BRITAIN’S CHEAPEST CHRISTMAS DINNER WHY GO ANYWHERE ELSE’ was found to be lacking, as it did not make clear the different weights of the products featured (Aldi, 20 March 2024).
By way of a further example, the ASA ruled that “The UK’s Best Network” needed to be backed up by objective evidence showing that Vodafone’s network had performed better in technical aspects such as coverage and reliability than the rest of the market. The ad did not include, or direct consumers to, objective evidence to support the claim, and was therefore not verifiable. The reference to the customer survey used (unsuccessfully) to evidence the claims was deemed insufficient to verify them (Vodafone Ltd, 28 July 2021).
In order to provide sufficient information for consumers to verify the comparison, it may be necessary to provide information about the methodology used when comparing products, and to make clear which competitors or products are being compared. In 2016, an ad stated the average customer saving when selling property based on their fees compared to if the UK average commission fee had been applied. This ad breached the Code, because it did not state, or provide a signpost to, information such as what the average sale price was, how that average (and their associated fee) had been calculated and the source of the average estate agent fee (New Broom Ltd, 14 September 2016). See also Procter & Gamble (Health & Beauty Care) Ltd, 2 December 2015 in respect of a ‘leading brand’ comparison.
Where the data (i.e. test results) used to support a claim is historic, and therefore cannot be replicated or checked for accuracy, it may be necessary to provide detailed data to make the claims verifiable. The ASA investigated variations of the claim “UK’s NO.1 5G network”, which featured in multiple ads for EE, and considered that the information was not sufficient to verify the claim. Because the test results were historic (i.e. specific to the six-month period of testing given the continuing roll-out of 5G after the testing period), consumers and competitors would not have been able to replicate the tests, regardless of whether detailed testing methodology was available. The ASA considered that for the claims to be verifiable, the result for each metric at each test location and time would need to be made available in an accessible format. Additionally, full particularities about the methodology by which the data was obtained, categorised, assessed, scored and ranked would need to be provided, so that the data could be fully understood and interpreted (EE Ltd, 23 August 2023).
Where, and how, should I provide the verification information?
- How to signpost to verification information
Ads should clearly explain how readers can verify a comparison. One way would be to direct consumers to a website that contains information about the basis (i.e. products, methodology, test results etc) of the comparison, and make clear that this is how consumers can verify the claim. Ads could, for example, include “comparison can be verified on www…” or “visit www… to verify the comparison” in small print. Merely including a website or postal address, without stating it is where consumers can verify the comparison, is unlikely to suffice.
In a Vodafone ruling in 2021, the ASA ruled that providing verification information immediately and prominently on a landing page to which consumers were taken would be sufficient to ensure a comparison could be verified. However, Vodafone had provided the verification information at the bottom of the landing page in small text, amongst other information, which meant the verification information was not immediate or prominent. The ASA also found the verification information which had been supplied to be insufficient (Vodafone Ltd, 28 July 2021).
In 2016, a TalkTalk product page included, amongst other comparative claims, the phrase "Market leading signal strength”. Although information about the basis of the claims was available to consumers, it could only be accessed by clicking and expanding a heading found under “Small Print” and clicking through to a page with another link to open the test report. Given the means by which to verify the claim had not been clearly signposted, and because not all of the necessary data and results were available, rule 3.35 was deemed to have been breached (TalkTalk Telecom Ltd, 1 June 2016).
Although an ad which included the claim “the largest breakdown provider” also included the text “more mobile mechanics than any other UK breakdown service” and a footnote which stated the source of the figures, this was not considered sufficient to verify the claim. While there was an indication that further information was available, it was not sufficiently clear that this was how consumers could verify the claim. The location of the footnote, at the bottom of the page, meant it could also have been overlooked (AA Ltd, 20 July 2022).
An Aldi ‘wraparound’ ad (where the ad covered the front and back page of a newspaper) was also found to lack the required verification information. The ASA held that information explaining how to verify the ad should have been included on both pages of the ad, as the separation meant some readers may only have seen the front page. The text that was included in an attempt to verify the claims was deemed likely to be overlooked by consumers, and was also considered to be insufficient (Aldi, 20 March 2024).
- Verifying by request
It is also likely to be acceptable to provide verification information upon request, by directing consumers to contact a postal or email address to obtain verification information (Wm Morrison Supermarkets plc, 26 August 2015).
- Making the verification information readily accessible
The information must also be readily accessible. Providing information behind a paywall will be insufficient. Although the claim “BEST DISHWASHER TABLET ON TEST” was supported by evidence, the test results could only be accessed by consumers who paid for a Which? subscription, so the claim was not verifiable (Procter & Gamble UK, 27 May 2020).
What about surveys, awards and test results?
Comparisons based on survey results or receiving third party awards must include enough information about the survey or award to ensure that the audience can verify the claim. These are likely to need to signpost consumers to information such as the sample size, the methodology, the group of respondents represented in the sample, which competing providers were included and the factors that respondents were required to consider when answering the question(s) on which the claim was based (HPI Ltd, 15 June 2016). See also Motorway Online Ltd, 30 November 2022 for similar considerations
Similarly, efficacy comparisons are likely to need to detail the methodology of the tests carried out, include a breakdown of individual results and make clear which products were tested (Medichem International (Manufacturing) Ltd, 13 April 2016).
Self-reported consumer data will not be sufficient to support a claim that would otherwise require objective substantiation. This type of data is unlikely to be sufficient to verify an objective comparison. See Vodafone Ltd, 28 July 2021 and Solvotrin Therapeutics Ltd, 13 June 2018. See Comparisons: Awards and consumer surveys for further information on these types of claims.
What if my comparison is based on confidential information?
Marketers are advised against making comparisons if the data cannot be made available to the public because, for example, it is confidential.
A complaint about an ad comparing supplements was upheld because the survey results were not in the public domain and could not be accessed by consumers to allow them to verify the claims (Solvotrin Therapeutics Ltd, 13 June 2018).