TL;DR
- Ofcom banned CPI-linked or RPI-linked mid-contract price rises for new mobile contracts signed from 17 January 2025 onwards.
- New contracts must state any price changes in pounds and pence, not as a percentage tied to an inflation index.
- Legacy contracts signed before January 2025 may still carry CPI+3.9% or RPI-linked clauses that remain lawful for their remaining term.
- If a provider applies an unexpected price rise to a new-style contract, you have a right to exit without paying an early termination fee.
- Ofcom's rules apply across mobile, broadband, and bundled services sold to residential customers.
Why Ofcom acted on inflation-linked price rises
For much of the 2010s and early 2020s, the major UK mobile operators built annual mid-contract price increases into their standard terms. The typical formula added 3.9 percentage points on top of the Consumer Prices Index, meaning the annual rise was both unpredictable and structurally higher than general inflation. When CPI peaked above 10% in 2022, many customers saw bill increases well above what they had budgeted for when signing a 24-month contract.
Ofcom opened a review and concluded that CPI-linked or RPI-linked clauses made it impossible for consumers to know in advance how much their contract would cost. In its 2024 review statement, Ofcom found that formulaic inflation-linked rises did not satisfy the requirement for price changes to be clear, transparent, and expressed in a way that a consumer could genuinely understand at point of sale. The regulator determined that reform was necessary to restore trust and enable effective comparison shopping.
What the January 2025 rules require
From 17 January 2025, any new residential mobile or broadband contract must comply with Ofcom's revised General Conditions. The core requirement is that if a provider reserves the right to change the monthly price during the minimum contract term, it must state the exact amount or the maximum amount of any future change at the point of sale. Vague references to "CPI plus a percentage" or "in line with the retail price index" are no longer permitted for new agreements.
Ofcom also requires providers to communicate any forthcoming price change clearly, giving customers adequate notice before it takes effect. If a change is not disclosed in a compliant manner at the time of sale, the provider cannot lawfully impose it during the minimum term. The rules cover contracts sold to individual consumers and micro-businesses defined under the General Conditions framework.
What "fixed price" means in practice
Some operators responded to the new rules by advertising plans as fixed-price for the duration of the contract, meaning the monthly amount shown at checkout is guaranteed not to change until the minimum term expires. Others chose a different route: disclosing a stated maximum uplift in monetary terms, such as confirming that the monthly price will not increase by more than a specified pound amount in any given year. Both approaches comply with Ofcom's requirement, provided the disclosure is made clearly at point of sale and again in the contract summary document.
Consumers should read the contract summary carefully before signing. The summary, which providers are required to supply under Ofcom rules, must set out the total minimum cost over the contract term and any scheduled price changes. If the summary does not contain a clear monetary statement about future price changes, that is a compliance red flag worth querying with the provider before committing.
| Aspect | Old model (pre-Jan 2025 contracts) | New Ofcom rules (Jan 2025 onwards) |
|---|---|---|
| How price changes were expressed | CPI + 3.9% or RPI-linked, announced each spring | Stated in pounds and pence at point of sale |
| Consumer ability to predict total cost | Impossible - depended on future CPI/RPI | Maximum future cost known at sign-up |
| Right to exit if price changed | Debated; Ofcom review found inconsistency | Clear right to exit if undisclosed change imposed |
| Contract summary disclosure requirement | Summary required but formula-based wording permitted | Summary must state exact or maximum uplift in £ |
| Applies to legacy contracts? | Yes - remains lawful for contracts in force before Jan 2025 | No - only applies to new contracts from Jan 2025 |
Legacy contracts and what they mean for existing customers
The January 2025 rules are not retrospective. A mobile contract signed in, say, October 2023 under terms that included a CPI+3.9% annual uplift clause remains subject to those original terms until it expires or is renewed. Ofcom confirmed this position in its implementation guidance: providers are not required to modify existing contracts, and customers on legacy agreements cannot invoke the new rules as a basis to exit without a termination fee simply because a CPI-linked rise applies.
However, if your legacy contract is approaching its end date, you are free to move to a new contract on the updated terms. Ofcom guidance also makes clear that providers must still apply the old formula correctly and notify customers before any annual rise takes effect. If a provider misapplied its own formula, or failed to give the contractually required notice, that would still give rise to a complaint.
The right to exit and how it connects to the new rules
Under Ofcom's General Conditions, a "notifiable price change" is one that is either not permitted under the contract terms or was not adequately disclosed at point of sale. When such a change occurs, the customer has a right to exit the contract without paying an early termination fee (ETF). The right must be exercised within a window set by the provider's notice, typically 30 days from the date the notification is sent.
For new contracts signed under the 2025 rules, the scope of notifiable changes is more tightly defined: if the provider attempts to increase the monthly charge beyond the amount stated at point of sale, that will almost certainly qualify as a notifiable change, triggering the exit right. Customers who wish to exit should write to their provider within the notice window, stating clearly that they are exercising their right to exit under Ofcom's General Conditions in response to a notifiable price change.
How complaints and enforcement work
Ofcom does not handle individual consumer complaints directly. If a dispute with a provider cannot be resolved through the provider's own complaints process within eight weeks, you can escalate to an approved Alternative Dispute Resolution (ADR) scheme. The two ADR schemes approved for telecoms are Ombudsman Services: Communications and the Communications and Internet Services Adjudication Scheme (CISAS). Both are free to consumers and can award compensation or direct a provider to change its practices.
Persistent or systematic breaches of Ofcom's General Conditions can result in Ofcom opening an enforcement investigation. Under the Communications Act 2003, Ofcom has the power to issue directions requiring compliance and, ultimately, to impose financial penalties. Consumers who believe their provider is systematically breaching the 2025 rules can report this to Ofcom via its online complaints portal, which contributes to the regulator's monitoring intelligence.
What this means in practice
Imagine Priya signs a 24-month SIM-only contract in March 2025 after the new rules came into force. The contract summary she receives states that her monthly charge is £18 and will not increase during the minimum term. In November 2025, she receives a text saying her bill will rise by £3 per month from December. Because her contract summary contained a clear no-increase commitment, this rise is a notifiable price change under Ofcom's General Conditions. Priya writes to her provider within 30 days of the notice, invoking her right to exit. The provider must release her from the contract without charging an early termination fee, freeing her to switch to another provider or renegotiate.
Related Guides
How we verified this
This article draws on Ofcom's General Conditions of Entitlement, Ofcom's 2024 review statement on inflation-linked price rises (published under the "Fairness for customers" programme), Ofcom's guidance on contract transparency and ADR schemes, and the Communications Act 2003 as published on legislation.gov.uk.
Disclaimer: Kaeltripton.com is an independent UK editorial publisher. We are not regulated by Ofcom or the FCA and we do not sell or arrange mobile services, insurance, or financial products. This content is for general information only and is not legal, financial, or technical advice. Rules, prices, and operator policies change. Verify the current position with Ofcom, GOV.UK, the ICO, or your provider before acting. ICO registered ZC135439. Last reviewed: 2026-06-05.
Frequently Asked Questions
Can my mobile provider raise my monthly bill mid-contract?
For contracts signed from 17 January 2025, a provider can only raise the price if the increase was clearly disclosed in pounds and pence at point of sale. For older legacy contracts, CPI- or RPI-linked annual rises may still apply if they were written into the original terms. In both cases, the provider must give adequate advance notice of any increase before it takes effect.
What are the new 2025 Ofcom rules on mobile price rises?
Ofcom's revised General Conditions, effective from 17 January 2025, require that any reserved right to change a monthly charge during the minimum term must be expressed as a specific amount or maximum amount in pounds and pence, stated clearly at point of sale. Vague inflation-index formulae such as "CPI plus 3.9%" are no longer permitted for new contracts.
Do the new rules apply to my existing mobile contract?
No. The January 2025 rules apply only to contracts entered into on or after 17 January 2025. If you signed your current contract before that date, the terms in place at signing govern any mid-contract price rises, which may include a CPI- or RPI-linked formula. The new rules will apply when you renew or take out a new contract.
How do I exit my mobile contract after an unexpected price rise?
If your provider notifies you of a price change that qualifies as a "notifiable" change under Ofcom's General Conditions — meaning it was not disclosed at point of sale or exceeds what was agreed — you can write to the provider within the notice window (typically 30 days) to invoke your right to exit without paying an early termination fee. Keep a record of the notice you received and your written response.
What is CPI and why did Ofcom ban it for mobile pricing?
CPI, the Consumer Prices Index, is a measure of general inflation published by the Office for National Statistics. Operators used CPI as a base for annual mid-contract bill increases, typically adding a fixed percentage on top. Ofcom found this practice made total contract costs impossible to predict at point of sale, undermining transparency and informed consumer choice, and banned it for new contracts from January 2025.
