Virgin Mobile and O2 customers face an inflation-busting 11.7% increase in the cost of their phone bills from April.

O2 said that the hike would enable it to “continue investing” in its services.

While the latest Retail Price Index (RPI) showed that inflation rose to 7.8% in January, Virgin Mobile has decided to add a further 3.9% to that figure for the cost of its future mobile plans.

The move comes a month after BT said that customers would have to pay £3.50 more for broadband and phone bills from 31st March.

Comparison site believes that the hefty price hikes set a bad precedent and has urged providers to let those affected “walk away” from contracts without a penalty. telecoms expert Ernest Doku said: “Mobile users cannot be expected to guess what future inflation rates will be when they take out their contracts.”

Virgin Mobile said that its customers already had an opportunity to switch providers for free last month when it informed them about the upcoming price changes.

All customers who remain with Virgin Mobile will have to pay 11.7% more this spring, but O2 has said that the full rate hike will be limited to those who joined the service after March 2021, though everyone else will still get a 7.8% bill increase.

A spokesperson for O2 admitted that price hikes are “never welcome” but added that its services still offer “incredible value”.

O2 also said that the price rise will be only applicable for the “airtime part” of most customers’ bills.