Warning on £90m cost of 'hidden' mobile contract clauses

Mobile phone companies could be making up to £90 million a year by legally using "hidden" contract clauses to raise the cost of what should be fixed-rate tariffs, the consumer group Which? has warned.

The organisation has filed an official complaint to regulator Ofcom after an investigation found that 70% of people on fixed contracts did not know that network providers could increase prices during the lifetime of their contract.