T-Mobile is to raise the prices of most of its monthly plans, in a move it has blamed on inflation.
The Everything Everywhere brand will increase its pay-monthly prices by 3.7 percent from 9 May, it said on Wednesday, adding that customers who had joined before 1 February would be affected.
Those on You Fix, Full Monty or other currently-marketed plans will not see price rises as those tariff schemes already take the raised pricing into account, T-Mobile said.
"We are sorry to say that we will be increasing the price of some of our monthly plans by 3.7 percent from 9th May 2012," a T-Mobile spokesperson said in a statement. "On a £15 plan, this would represent a £0.55p monthly increase."
"The increase is a result of the rising costs of the business, linked to inflation, as well as our desire to continually invest in our network and propositions to provide the best service for our customers," the statement continued.
T-Mobile stressed that it was only the contract prices that were changing, and out-of-bundle charges would stay at their current rates.
As T-Mobile's support page points out, customers cannot cancel their contracts as a result of the price hike, as the rise is in line with inflation.
"Our pay monthly terms and conditions allow us to increase charges up to the Retail Price Index (RPI) figure in any 12 month period," the page states. "The increase in your price plan charge is not more than the 3.7 percent rate of inflation as measured by the RPI in February 2012. If you still wish to cancel your contract, you'd need to pay any cancellation charges that may apply."