At the start of the year, broadband providers were told to improve the way they advertise the price of deals after joint research by the Advertising Standards Authority (ASA) and communications regulator Ofcom found a majority weren’t able to calculate the total costs of a contract deal.

A May deadline was initially given for providers to improve the way deals were advertised but this was pushed back to today to give them enough time to make the changes.

From now on, in order for broadband providers to ensure they stay within the rules, their advertised price should:

• Show all-inclusive up-front and monthly costs; no more separating out line rental
• Give greater prominence to the contract length and any post-discount pricing
• Give greater prominence to up-front costs (such as delivery fee, activation fee, installation fee).

Dan Howdle, telecoms expert at Cable.co.uk, said the ruling represents “one of the biggest shake-ups the UK broadband market has ever seen”.

He said: “Even under these new rules, providers are still able to splinter off costs like internet security and whether you’re able to watch your TV service in high definition. It’s the nature of the industry: Providers will always do whatever they can to make things appear cheaper than they actually are.

“But the real elephant in the room here is that, even if we do reach a stage where the prices advertised match those customers actually pay in all cases, broadband remains the only essential utility we buy without knowing exactly what we’re paying for.

“No one pays a flat tariff for a mystery quantity of gas or an unknown number of kilowatt hours, and yet this is exactly the situation with broadband.”

If companies are found to breach the new rules, the ASA can ask them to amend or remove the advert.