Customers on Orange and T-Mobile are facing rises in the price of their monthly contracts from the middle of April.
Parent company EverythingEverywhere has blamed rising costs for the move. However, critics have called the rise a cynical attempt to increase profits after the operator revealed customers would be able to avoid the rises by signing up to a new 'Fix Your Monthly Plan'.
The increase is believed to be around 79p per month. The move is expected to add £52m to the company's bottom line.
The new plan – which will allow EE customers to fix the current price of their contracts for between 50p to £2 – is set to launch on April 10th 2013, the same day price rise is due to come into effect.
Speaking to The Guardian, a spokesperson for EE said that customers' terms and conditions clearly state that the company can raise the price of its contracts midway through a contract, based on rises in the Retail Price Index (RPI).
"Customers are encouraged to read the terms and conditions and have a 14-day period in which to change their minds," the spokesperson said. "If customers are unhappy they can break their contract if they pay a fee for leaving us early."
It isn't the first time T-Mobile and Orange have increase the price of customers' contracts midway through their plans. O2 also announced a rise in its contract prices based on the RPI earlier this year.
In an attempt to put the rise in perspective, it claimed that it was no more than a can of baked beans a month. However, one critic of the rise described it as an expensive can of baked beans.