Premium number regulator PhonepayPlus is setting out new measures to help protect mobile users from unscrupulous content providers.
The watchdog reported a 108 per cent jump in the number of mobile-related complaints received in the past year, and has consulted with various stakeholders in the market to address the problem.
PhonepayPlus has published a final statement (PDF) which lays out guidelines to help reduce customer complaints and rebuild trust in the services.
Under the new rules providers must first send a free confirmation text message to potential new customers, detailing the cost and conditions of the service, before they can become subscribed. Consumers cannot be charged until they have confirmed the subscription by replying to the text.
Furthermore, providers offering mobile subscription services that cost more than £4.50 in any given week, or those that use pay-per-page charges on the mobile internet, must first gain permission from PhonepayPlus.
Premium mobile services are used for a variety of purposes, including competition entries and the delivery of news and other information, as well as content downloads such as ringtones, wallpapers and mobile games.
PhonepayPlus said that, while many people use these services successfully and without incident, the organisation has seen a sharp increase in complaints, and said that some individual cases have involved bills of thousands of pounds.
"There are many innovative, useful and fun services available to consumers via their mobiles," said Paul Whiteing, acting chief executive at PhonepayPlus.
"These new measures are targeted at a small number of providers who do not offer services to customers in a fair and straightforward way. Consumers should not need to work hard to understand the full price of any service."
PhonepayPlus has also issued a Statement of Expectation (PDF) as a summary to help service providers comply with the new regulations.
The statement includes stipulations that price information must be clearly displayed, and that providers sending free promotional messages must make it clear how to opt out of receiving similar messages in the future.
Providers offering subscription services or sending promotional text messages must also enable consumers to easily opt out of the service via the 'Stop' command. Failing to do this will result in the service being immediately shut down pending an investigation by PhonepayPlus.
"The guidelines are the result of intensive research into the mobile market, and PhonepayPlus expects them to result in fewer complaints and greater confidence in the market," concluded Whiteing.
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago