The national press ad carried the headline Public Notice and implied it was from a public authority, giving the impression that BT's new service had, unlike rivals, official backing.
The 118 500 service is just one of many being launched by a number of telecoms firms looking to break into the market that BT once dominated via 192, which was axed by regulator Oftel to increase competition in the market.
However, following a series of complaints from a number of parties, including the telecoms watchdog, rival Centrica and members of the public, the Advertising Standards Authority ruled that the headline could dupe consumers into thinking that it was an official notice.
BT defended the ad, saying it did not purport to be a public authority, and that the use of the phrase "public notice", was designed to capture the audience's attention. It said the ad also included various mentions of BT and its logo, which made it clear it was from a commercial company.
The company agreed to amend the copy and said it would not use this tactic again in an ad campaign.
The complaints ranged from the implication that 192 was only being replaced by one number, when in fact a number of services would be on offer; to the fact that the ad implied that BT had launched the service off its own back, when the new services had been launched following the regulator's intervention.
The ad escaped censure for omitting to mention that the service is not available on some networks, such as Telewest and NTL.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .