Broadband providers will only be able to advertise "average" download speeds if at least 50 per cent of customers are able to receive them at peak times, under new rules announced today by the advertising regulator.
This marks a change from the current position that advertised "up to" speeds if they were available to at least 10 per cent of customers.
The guidance will take effect on May 23 after a six-month implementation period and apply to residential broadband services.
The Committees of Advertising Practice also recommends that speed-checking facilities, like those provided on internet service providers' websites, should be promoted in ads wherever possible.
It follows moves by Ofcom to introduce automatic compensation for anyone suffering from slow repairs, missed appointments, or delayed installations to their broadband or landline services.
CAP director Shahriar Coupal said: "There are a lot of factors that affect the broadband speed a customer is going to get in their own home; from technology to geography, to how a household uses broadband.
"While we know these factors mean some people will get significantly slower speeds than others, when it comes to broadband ads, our new standards will give consumers a better understanding of the broadband speeds offered by different providers when deciding to switch providers."
CAP's sister body, the Advertising Standards Authority, also today ruled that it is not materially misleading to describe broadband services that use fibre-optic cables for only part of the connection as "fibre broadband". ®