Telecoms and media regulator Ofcom will change the rules governing premium rate phone services to include mobile based services next month, it has said. It is making the change to clear up what it calls ambiguity in the current rules.

Premium rate phone services are regulated by the Independent Committee for the Supervision of Standards in the Telephone Information Services (ICSTIS), which follows an Ofcom approved code. That code applies to communications providers, but the code has always exempted those providing "a Mobile Service, a Personal Numbering Service or a Radiopaging Service", according to Ofcom.

That means that anyone who breaks ICSTIS rules but comes under that exemption cannot be referred to Ofcom, and cannot have action taken against them by Ofcom under the terms of the Communications Act.

The exemption was intended to exclude from regulation normal calls to mobile phones and other mobile services which the regulator said should not count as premium rate services even though they were relatively expensive.

Ofcom will delete the exemption altogether in a revision of the premium rate services condition in exactly one month's time.

The change is the result of two consultations. The first consultation propsed changing the exclusion so that it excluded not “mobile services” but “calls to mobile services”, " thus removing any perceived uncertainty as to whether calls from mobile phones to premium rate services were or were not also excluded from the definition", according to an Ofcom statement.

But during further consultation Ofcom was told that the amendment was at least as confusing as the original statement. "That modification had the potential to itself cause confusion, thereby substantially defeating the purpose of making the modification in the first place," said the Ofcom statement.

A second consultation was conducted, following which Ofcom decided to scrap the exclusion altogether. "Such removal would enable the clarification that Ofcom was seeking to provide to be delivered in a neat and simple way that did not have an apparent potential to itself give rise to confusion as to what the definition did and did not capture," said the Ofcom statement.

"That view was fully in accordance with the original intention behind the exclusion, namely, to make clear that ordinary calls to mobile phones and other services which enabled the called party to be reached irrespective of his or her physical location were not within the scope of [the regulation]," it said.