A TV advert for TalkTalk's unlimited broadband service has been banned by the Advertising Standards Authority (ASA).
The marketing regulator deemed that the ad - which referred to "a network connection that’s a whopping 99.9% reliable" and called on consumers to "switch today" - had the potential to mislead customers on two counts.
A number of customer complaints were submitted to the ASA, amid concerns over whether the claim could be substantiated, and who could actually benefit.
"We considered most consumers would be interested in the reliability of their end-to-end broadband connection up to the point of their router or into their home, rather than the reliability of certain portions of the overall connection," the ASA stated.
"There were external factors that would affect overall connection reliability, which we understood TalkTalk would not have control over."
As such, the regulator said the evidence did not substantiate the likely interpretation of the claim, meaning the advert was misleading.
On the second issue - the benefits customers would actually receive by switching - TalkTalk was reprimanded for not making the conditions clear.
The ASA added that consumers might interpret “switch today” to mean they could change to a different package as a TalkTalk customer.
"Because the ad did not make it clear that the package was only available to new customers, we concluded it was misleading."