The Advertising Standards Authority (ASA) has published new guidance for broadband providers to follow when advertising internet packages.
Following a lengthy investigation of broadband marketing practices, the ASA has moved to ensure all consumers receive transparent information about the services on offer.
Ofcom has previously raised concerns about a lack of clarity in the broadband market, with subscribers often unable to access anywhere near the advertised headline speed.
Broadband providers will now be subject to greater restrictions when advertising 'up to' download speeds.
Under the new ASA regime, which comes into force in April 2012, broadband providers must be able to demonstrate that advertised speeds are achievable by at least ten per cent of users.
Broadband speed claims must also be accompanied by a warning, which alerts consumers to the fact they may not be able to achieve the headline download capabilities.
Back in March, Ofcom revealed that the average broadband speed in the UK was 6.2Mb.
However, the average 'up to' broadband speed advertised by service providers was found to be more than double – 13.8Mb.
Results were compiled based upon more than 18 million performance tests in 1,700 homes at the end of 2010.
Ofcom Chief Executive Ed Richards said it was "important" that the rules surrounding broadband advertising are changed.
He added that consumers should be given the opportunity to make more informed decisions about the broadband packages they select.
The ASA has also acted to ensure consumers realise how much data they are able to consume each month.
Where usage allowances are concerned, the term 'unlimited' may only be used if there is no risk of additional charges being incurred by the customer based upon data consumption.
If broadband providers offer a fair usage or traffic management policy, they will not be permitted to use the 'unlimited' description.