Ads for the speed of the broadband that violate the rules will enter into force on the 23 May will be banned, the Advertising Standards Authority has said.
The ASA’s new rules require providers to include a median average speed for the service between 20:00 and 22:00.
Providers will no longer be able to advertise the “speed”, which may currently be available to only 10% of their customers.
And have to give details of any limitations that may affect speed.”Fair warning”
“If a broadband provider is making speed claims in its ads of the post-May 23, then you will have to keep proof to demonstrate that the basis on which the claim is made,” an ASA spokesman told the BBC.
“Numerical speed claims in broadband ads should be based on the download speed, for at least 50% of the customers at the time of the peak described in ads as “mean”.
He added that the broadband providers had been given fair warning, and “we expect them to bring their ads in line with the guidance.”
But some experts fear the new rules will cause confusion for consumers. Appear faster
“The new rules mean that very different figures will appear in advertising, suppliers, sites, and comparison ads,” said Andrew Ferguson, from the news website Thinkbroadband.
“And there is much more room for confusion, or for service providers to game the system to appear more quickly than their competitors.”
Thinkbroadband has been conducting its own speed test for the most common packages between 20:00 and 22:00.
And Mr Ferguson said: “The speed is much lower than the current primary rate quoted in advertising.
“The key message is that people should take the advertised speed with a pinch of salt and the estimate will always be given during the preliminary phase of the order of the stages on the website of the provider.
“Broadband providers that have signed up to the Ofcom voluntary broadband speeds code of practice should provide an estimate of individual and have done for some years now.
“The changes in the rules of advertising will not change that.”