Up to 15 million O2 customers will see their monthly phone bill rise more than expected in April 2026. Money Saving Expert Martin Lewis has slammed the mobile phone provider for increasing annual bills by up to £30 a year, a 40% increase on what was written into customer contracts of £21.60.

He slammed the decision as a “mockery” that could push other network providers to follow suit. Mr Lewis said: “This move feels to me a bit like it makes a mockery of Ofcom’s new ‘pounds and pence’ consumer protection regime, which came in at the start of this year.”

Customers on unlimited data plans will feel the smallest change at 7%, going from £33.99 to £36.49. However, those on a 50GB tariff priced at £8.50 will see their prices increase to £11, nearly a 30% increase. 

In January 2025, Ofcom required mobile providers to clearly show how much bills would increase during the contract period before people sign up, which Mr Lewis said was the regulator’s solution to “hideous above-inflation mid-contract price hikes”. 

However, the money expert said: “Now O2 is also dancing away, increasing contracts by more than it said it would when people signed up.

“And while that means all its impacted mobile customers can leave penalty free – and many should- we know few will, most will likely just have to suck up a rise that was more than they were told when they signed up.”

He added: “And it’s worth noting the rises O2 had told customers of in advance were already usually far above inflation, but now will typically be at least 7% and up to 30%. And all this adds more inflationary pressure to the economy in its own right.”

After “O2 has opened the door to this behaviour”, he fears this will lead to other companies to feel “less worried” about also hiking their prices mid-contract.

Mr Lewis noted Sky, which he said “side-stepped” the price and pence change by saying it would allow customers to leave penalty-free when it did the annual hikes and would not tell customers of the rises before they signed up.

He added: “It’s a great regret that when Ofcom consulted on these changes it didn’t listen to the proposal I and others made to simply ban above inflation mid-contract price rises (or any mid-contract rises).

Ernest Doku, Uswitch mobiles expert, said: “Just weeks after Virgin Media raised broadband prices, O2 has followed suit, announcing a new mid-contract policy that will hike airtime costs by £2.50 a month for all customers, starting in 2026. 

“Kicking in from April 1, 2026, this change adds a huge increase proportionally for customers on cheaper deals. On O2’s £8.50 SIM only 12 month contract with 50GB data and unlimited calls and texts, this represents a staggering 29% increase annually.

“This move puts O2’s mid contract price rise at the higher end of the scale of mobile providers’ increases to date.”

Mr Doku added that, with different networks taking changing approaches to price increases, “it’s never been more important to compare deals available to you to make sure you’re getting the best deal”.

He said: “Since the increase applies to new and existing users, O2 customers don’t have to put up with this increase and can leave their contracts penalty-free. It only takes a few minutes to run a comparison, and there are plenty of mobile providers such as SMARTY, Lebara and VOXI who don’t raise prices mid-contract.”

A statement on O2’s website reads: “From April 2026, the monthly price of your mobile plan will be increasing. We’re letting you know now so you can plan ahead and be prepared.

“Each April, your airtime plan will increase by £2.50 for voice plans and 75p for data-only and smartwatch plans.

“We understand price rises are never ideal and want to reassure you this will only affect your airtime plan, with the cost of your device remaining frozen.”