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.


In light of the ASA’s consumer research findings and public consultation, CAP announced, on 23 November 2017, that the current, most commonly used approach to presenting speed claims in broadband ads is likely to mislead consumers. As a result, it is has published new guidance on the advertising of numerical speed claims for residential broadband services, which will take effect from 23 May 2018. Until then, the current guidance will apply, and this Advice Online will be updated when the new guidance comes into force.

The principle behind the current guidance, which also applies to mobile data services, is that speed claims must be based on consumers’ actual experience. The guidance is mainly concerned with download speeds, as they feature more frequently in broadband marketing communications, but upload speed claims should also conform to the guidance where relevant.

Advertisers can make a numerical speed claim to set out the maximum speed of their service if 10% of the relevant customer base achieves that speed and the claim is prefixed with “up to”. The substantiation required for speed claims must be robust and reasonably representative of actual performance, the Help Note explains in detail what type of substantiation is likely to be acceptable for both mobile and fixed line broadband services.

The reasons certain customers cannot achieve the headline speed should be stated in the ad, for example by referring to the effects of signal attenuation on ADSL2+ services (usually translated to the consumer as “speeds will vary depending on distance from the exchange”), or by stating that a traffic management policy applies at peak times. Qualifications should be prominent, and included in the body copy of the ad.

In some circumstances, further qualification will be needed. If a significant proportion of consumers receive a maximum speed that is so much lower than the headline speed that they cannot carry out normal online activity, for example streaming content, it is likely the advertiser will need to include one of the following statements:

“X% of our customers receive speeds below YMbit/s”

“X% of our customers receive speeds above YMbit/s”

“X% of our customers receive speeds between YMbit/s and ZMbit/s”

It is for advertisers to decide the values of X, Y and Z in the examples above, and that qualification will need to be in the body copy. Obviously the inclusion of that type of qualification in an ad for an ADSL2+ service will mean there is no need to refer to the effects of signal attenuation.

See Location specific claims, Superfast and 4G claims, CAP’s current Advertising Guidance note on the Use of speed claims in broadband advertising and the new Advertising Guidance note on broadband speeds.

Updated 23 November 2017


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