The TV ad, created by CHI & Partners, featured a voiceover that asked: "Would you like to save over £140 a year on your calls and broadband? Well it couldn't be easier."
On-screen copy read "Save over £140", while small print at the bottom of the screen specified TT Essentials' connection fees and line rental charges.
The voiceover continued: "Simply switch to TalkTalk and you'll pay £6.99 a month for your calls and broadband and join our customers who are already saving an average of over £140 a year."
The on-screen text changed to "£6.99" and the small print cited 2010 ICM Research conducted among 1,001 new TalkTalk customers.
BT objected to the ad on two counts. First, that the ad was misleading because it exaggerated the savings customers were likely to achieve by switching to TalkTalk, and secondly, that the savings claim was based on those made by customers who had already switched to TalkTalk, and not on savings that could be achieved by customers defecting from other providers.
TalkTalk argued that because the "Save over £140" statement was surrounded by question marks, it indicated that it was a question, not a claim, and that the voiceover's invitation to "join our customers who are already saving an average of over £140 a year" implied that the amount was not what viewers would definitely save, but what others who had switched had saved.
With regard to the second complaint, TalkTalk said that the material information with regard to the survey was set out in a "clear, intelligible and unambiguous manner via the voiceover", adding that the survey did not seek to make a comparison with a specific competitor.
The ASA noted TalkTalk's comments that the ad asked a question about savings, but disagreed that the on-screen question marks made the point clear.
It also judged that, although the savings claim was based on a survey, the methodology was not "sufficiently robust to support a savings claim, because customers who had switched to TalkTalk were more likely to have done so if they were going to make a saving, and the survey results were therefore unlikely to include data for customer for whom a switch would result in either no saving at all or only a small saving".
The ASA ruled that the ad must not be shown again in its current form.