The Advertising Standards Authority said that from 31 October, such ads should not separate line rental from prices, "give greater prominence" on the contract length, post-discount costs and up-front payments.
It follows the ASA’s joint investigation with Ofcom in January which found that just 23 per cent of participants were able to identify the total cost per month for a service after watching the ad once.
Twenty-two per cent were not able to recall the information after a second viewing. Eight out of ten (81 per cent) could not calculate the total cost of the contract promoted in the ad.
The news comes on the same day that the ASA has banned three BT ads, as part of the same campaign, for being unable to substantiate the claims made in the spots.
Two ads claimed that BT Infinity 2 is faster than Virgin Media when playing games and watching videos. The third alleged that BT Infinity has faster download speeds than Sky.
One complainant, who had used BT and Virgin, asked whether the claims could be substantiated given that they had used both services and had not noticed a difference.
Sky questioned whether the claims in the third ad could be substantiated and whether sufficient information was provided for the comparison.
BT responded saying that the metrics for performance were based on "jitter (the variation and stability of data transfer); latency (how long data packets took to transmit); upload speed; and packet loss (which would affect the quality of the transmission)".
It measured the speeds against this and provided a table on the results to the ASA.
In terms of the Sky complaints, BT provided data on fixed-line data. However it said it was unable to gain consistent wireless performance to do the tests because it depended on the demands on the network.
Therefore it tested the wireless router connection separately to the fixed-line speed, saying that Ofcom had "applied this principle in a recent app launched to measure the quality of home wireless connections".
BT also said that it provided verification details on its website and included the link in the ad.
However the ASA did not agree that the data provided was sufficient data and adequately substantiated its claims.
Guy Parker, the chief executive at the ASA, said: "We recognise the importance of broadband services to people's lives at work and at home.
"The findings of our research, and other factors we took into account, showed the way prices have been presented in broadband ads is likely to confuse and mislead customers.
"This new tougher approach has been developed to make sure consumers are not misled and get the information they need to make well-informed choices.
"We’ll support the broadband industry as they move towards changing their approach in time for the October 31 deadline."