The Advertising Standards Authority has banned a British Telecom advert promising "instant internet" on grounds that it failed to substantiate its claims.
In the national press ad, BT promoted its BT Infinity fibre optic broadband service as being the "birth of the instant internet". The firm said that the service would allow users to "instantly" stream high definition movies and TV shows, as well as access multiple websites and download songs.
The ASA received four complaints about the use of the word "instantly" being misleading because BT's broadband is high speed, but it still has delays.
BT attempted to argue that the phrase "instant internet" purely referred to the very short time that it would take users to get online.
The telecoms giant supplied evidence to the ASA that its fibre optic broadband enables users to upload a 9Mb video in eight seconds or download a 6Mb song in three seconds.
It also claimed that HD streams from catch-up services such as BBC iPlayer take between three and four seconds to start, but then stream constantly.
BT said that the word "instant" was not intended to mean the "complete absence of any delay or zero seconds". The firm gave the example of instant coffee and instant hair removal cream, which consumers understand are not actually "delivered instantly", but have to be prepared.
In its ruling, the ASA judged that most consumers would understand the majority of claims being made in BT's advert, including the references to HD movie streams or music downloads.
However, the watchdog decided that BT had not provided sufficient evidence to support the speed and performance claims for all customers, all of the time.
"We had not seen evidence that substantiated those times, or that showed what speeds could be achieved by customers using BT's fibre optic broadband, and that those speeds would be achievable by customers at times of high user demand and with non-optimal computer set-ups," said the ASA.
"We noted the three customer profiles and two videos submitted by BT, however, we did not consider that profiles and testimonials alone were sufficient to substantiate claims relating to the speed of a broadband service.
"Because we had not seen evidence to support the claims made in the ad, we concluded that it was misleading."
After finding the ad in breach of advertising rules relating to substantiation and truthfulness, the ASA said that it "must not appear again in its current form".