Millions of broadband and mobile users face inflation-busting price increases in April may wonder where the communications regulator has been as it has only just appeared to have noticed what the companies it regulates are up to.

Customers who shopped around for the best broadband or mobile deal are now facing increases of up to 17% depending on which inflation index their supplier uses for intra-contract increases.

Deep in the small print the companies have the right to increase the monthly prices by the consumer price index in December – 10.5% - plus around 4% or by the January retail price index published in mid-February and likely to be around 14% plus around 4%.

The regulator has strict rules that contracts must make it clear how much prices can increase. Unfortunately customers who signed for a two year contract this time last year cannot have believed that they were signing up to price rises of up to 17% half way through their contracts.

Ofcom has announced it is looking into whether companies have been making the potential price rises clear before customers sign up. By the time they publish their findings “later in the year” inflation should be about half the current rate.

The regulator estimates that about a third of customers do not know if their company can out up prices or how such increases would be calculated. Its review will decided whether tougher protections are needed.

In the meantime it has pointed out that many customers are out of contract and can leave their current provider and move to one that is better value, negotiate better contract terms with their existing provider or change what their contract covers to save money.