The Advertising Standards Authority (ASA) has told broadband providers to ensure future speed claims in ads are based on average speeds at peak times.
Providers are currently allowed to advertise broadband speeds if they are available to ten per cent of their customers.
However, the ASA has been concerned for some time that this could potentially mislead people, with the majority of customers possibly not getting the speeds they expected.
Following a consultation by the Committees of Advertising Practice (CAP), the watchdog is therefore imposing new rules, which state that advertised speeds should be based on the download speed available to at least half of customers at peak times and described in the ads as "average".
Furthermore, the ASA wants providers to ensure their ads recommend speed-checking facilities wherever possible.
The new rules take effect from May 23rd 2018, which means the sector has six months to prepare for the changes.
Shahriar Coupal, Director of the CAP, believes the new standards will give consumers a better understanding of the broadband speeds offered by different providers when they are looking at switching.
"We continually review our standards to make sure they reflect consumers’ experiences, the technology available and the evidence base to make sure our standards are in the right place," he commented.
"Following extensive research and consultation, we hope our new standards will improve customer confidence in future ads.”
Digital Minister Matt Hancock has welcomed the announcement, as he believes that headline "up to" speeds that are available to just one in ten consumers are "incredibly misleading".
"Customers need clear, concise and accurate information in order to make an informed choice," he said.
"We have been fighting for this for some time now, and it’s a great victory for consumers."
Richard Neudegg, Head of Regulation at uSwitch.com, added: "Currently 90 per cent of broadband customers can be left disappointed by a service that will seemingly fall short of the speed they’ve seen advertised.
"Today’s announcement should reduce the disappointment to 50 per cent of customers from May 2018.
"Whilst this change might reduce the number of consumers that feel let down, the reality is that a national advert can never accurately communicate broadband speeds because speeds are so specific to your individual property.
"In order for the industry to deliver broadband services that better align with consumer expectations, providers need to allow for far more straightforward ways to quickly and easily compare the services and speeds available from different suppliers at their own home, side-by-side.
"While today’s announcement marks a step in the right direction, we hope to see the industry embrace more innovative transparency measures so that consumers can more easily identify the service that suits their needs."