Ofcom has issued a new set of guidelines relating to the small print sometimes included in broadband packages offered by providers.
The publication comes in the wake of research from Moneysupermarket which found that 27 per cent of broadband users are "falling foul of extra charges".
Ofcom has reminded broadband companies that they must make add-ons such as charges for non-direct debit payments clear to the customer.
According to the industry watchdog's chief executive Ed Richards: "When consumers shop around for the best deal, they should be able to easily assess the true cost of what's on offer.
"We want to make sure that telecoms and pay-TV companies are up front about all their charges and, where there are small print charges, they must be fair."
It was also stipulated that extra costs which are not part of the standard price paid by customers for broadband subscription should be "fair".