The Advertising Standards Agency (ASA) has hit out at both BT and TalkTalk for separate transgressions, laying down the law on both companies for misleading customers.

The group found that BT had misled O2 broadband customers regarding a claim that Sky was set to shut down their network without warning following its purchase of the service last year, and that TalkTalk had misled customers into thinking it had the cheapest ‘unlimited’ broadband package available on the market.

The ASA was asked to investigate BT by Sky parent company BSkyB following a direct mail campaign sent out by the telecoms group claiming that the latter would switch off O2’s broadband by April 2014 without notifying customers, a claim BSkyB ardently denied.

BT argued that the O2 Broadband acquisition had been public knowledge since March 2013 and that customers would be switched to BSkyB’s network, but the ASA disagreed, saying that the "switch off" allegation was misleading and "did not mirror the information that had been communicated to O2 broadband customers".

Talk that Talk

In a separate ruling, the ASA also acted against network provider TalkTalk, ruling against the company’s claim that it offered "Britain’s lowest priced totally unlimited broadband".

TalkTalk ran several print and online adverts promoting this claim, prompting complaints from BT and another unnamed service provider, which the ASA upheld on the grounds that the claims were unsubstantiated, wrong on price comparisons, and misled customers.

"We told TalkTalk to make clear the basis of their comparisons in future, and to ensure that significant information relating to those comparisons was given sufficient prominence," the ASA said in a statement.

TalkTalk, which said had been using the tagline "Britain’s lowest price" since November 2013 without any complaints, had argued that the pace of promotions by its competitors changed so quickly that any comparisons would "soon be out of date and then potentially misleading"

"We’re committed to making Britain better off and consistently offer our customers Britain’s best prices for TV, broadband, mobile and home phone," a TalkTalk spokesperson said after the ruling.

"As such TalkTalk homes make significant savings in comparison to our competitors. We note the ASA’s comments about ensuring comparison text is prominent and look forward to continuing to provide Britain’s lowest prices."