For years, most UK mobile contracts carried a clause allowing the price to rise every spring by the rate of inflation plus a few percentage points. When inflation spiked, so did bills, and the increases were impossible to predict when you signed. That model is on the way out.
What the rules say now
Since January 2025, Ofcom has required providers to set out any mid-contract price rise in pounds and pence, up front, at the point of sale, rather than as a percentage linked to an inflation index. So a contract taken out today should tell you plainly: "your monthly price will increase by £X on [date] each year". If a retailer's listing does not show this, ask before you commit.
This applies to new contracts. If you are still on an older agreement, its original inflation-linked clause may still apply until you sign a new one.
Why it still matters when comparing deals
Two deals with the same monthly price are not the same if one rises by £1.50 each April and the other by £3. Over a 24-month contract that includes two increases, and on a 36-month device plan, three. The fixed increase is usually a small fraction of the total, but on close comparisons it is the tie-breaker.
Our deal cards show the price and total cost as the retailer's feed reports them today. Scheduled increases are set out on the retailer's own checkout page, which is worth reading before you click buy.
Plans that do not rise
A number of smaller networks and SIM-only brands advertise fixed prices for the length of the plan, and rolling 30-day plans by their nature cannot lock you into an increase — if the price goes up you simply leave. If predictability matters to you, filter SIM-only plans to 1-month terms and look for "no price hikes" among the perks.
If you are hit with a rise you did not expect
Where a provider changes your contract in a way that was not clearly set out when you signed, you may have the right to leave without an early-termination fee. Ofcom's guidance covers this; contact your provider first and quote it if needed.