A mobile phone coverage checker on provider EE's website has been ruled misleading by the advertising watchdog for not making clear that it is "only a guide".
The Advertising Standards Authority (ASA) received a complaint from a T-Mobile customer after parent company EE reported that 3G coverage for his postcode was "excellent" when the man had no mobile phone signal at home and a poor signal outside.
The man said the results displayed when he entered his postcode read UK mobile coverage for 3G calls and internet was "excellent", with further text saying: "Fast, reliable internet access and high quality calling. Available on 4GEE, Orange and T-Mobile plans."
Upholding the complaint, the ASA said: "We considered the ad did not make sufficiently clear that the claims that appeared under the 'coverage results' were intended as a guide and that coverage could be affected by a range of factors.
"We therefore concluded that the ad breached the code." It added the advert must not appear again in its current form.
Unilever has donated £18,000 to the RSPCA following hundreds of complaints that its Marmite ad trivialises the work of animal welfare agencies.
Some 400 complaints have been lodged by television viewers since the documentary-style spoof, which featured officials was screened on Monday evening.
The ad featured a team of welfare officers go into homes and reclaim "neglected" jars of Marmite from their owners.
A new Marmite advert in which a team of welfare officers go into homes and reclaim "neglected" jars of Marmite from their owners has triggered over 330 complaints to The Advertising Standards Agency (ASA) since it was first aired on Monday.
The ASA confirmed that it had received 330 complaints with viewers arguing that the advert was in "poor taste" and "deeply offensive".
A spokesman for the authority said: "The complainants say it is in poor taste while others maintain that it is deeply offensive. Some have objected that it trivialises the work of both animal welfare charities (RSPCA) and child protection agencies."
The ASA said complaints were still being monitored but stressed that no further action was currently being taken.
There was a mixed reaction to the advert on the company's Facebook page.
Some users complained that the advert was " trivialising cruelty", with one user labelling it "distasteful" and "inappropriate".
An advert for Heineken beer has been banned for appearing to encourage the illegal act of drinking alcohol in a football stadium.
The television ad showed a man on a remote island receiving tickets for the Champions League final, grabbing two bottles of Heineken and making his way to Wembley Stadium.
The final scene showed him arriving at the event and taking his seat next to a woman, with the two of them clinking the bottles together in a celebratory fashion.
Heineken argued that the ad set out a "light-hearted fantasy" but the Advertising Standards Agency said: "We concluded that the ad was socially irresponsible because it condoned or encouraged behaviour that was either illegal or not permitted."