Icstis has also announced new rules which force quiz-based TV shows like Brainteaser to tell viewers their chances of getting through, and how much it will cost.
Icstis said it had worked closely with Ofcom, broadcasters, producers and telephone companies, "who have all been supportive in making sure that the changes could be introduced as soon as possible".
Icstis plans to introduce a licensing regime for the phone service providers that will make it easier and clearer to define which companies are responsible for ensuring that consumers entering competitions get fair treatment.
"We believe these new measures, which are designed to address the concerns that have been raised recently, will go a long way to restoring consumer trust in this form of TV quiz, " said Icstis chief executive George Kidd.