The Advertising Standards Agency (ASA) has pledged to make sure broadband consumers are not misled by speed claims in ads, following the introduction of new rules.
Providers had been allowed to advertise broadband speeds if they were available to ten per cent of their customers.
However, from today (May 23rd), they must ensure speed claims in ads are based on the download speed available to at least half of customers at peak times and described in the ads as "average".
Guy Parker, Chief Executive of the ASA, commented: "From today, consumers will see a difference in broadband ads that make claims about speed as this new, tougher, standard is enforced.
"We’ll be making sure consumers aren’t misled by speed claims in ads, not least because choosing the right broadband deal has become such an important part of running a household or business."
The change in the rules has been welcomed by the Internet Service Providers' Association (ISPA), which stated that it will bring "greater clarity" to broadband customers.
Andrew Glover, Chair of ISPA, said its members are committed to meeting the new obligations regarding median averages, and ensuring all the relevant information is clearly set out for consumers before they sign up.
He went on to state that this is a "significant move towards greater consumer understanding and informed expectations of broadband speeds".
However, he stressed that broadband speeds are "subject to contention and not a dedicated service", and can be affected by factors inside homes that are outside the provider's control.
Mr Glover added that consumers also view speeds as "one part of the overall package available to them", as issues such as reliability, price and customer support also need to be considered.