TL;DR
- An early termination fee (ETF) cannot lawfully exceed the remaining monthly charges you would have paid, minus any costs your operator saves by ending the contract early.
- Ofcom’s General Conditions require ETFs to be proportionate and reflect actual loss, not a penalty charge.
- Operators must tell you the maximum ETF before you sign and must recalculate it monthly so it reduces as the contract runs.
- If you believe an ETF is excessive you can challenge it in writing; escalate to the approved ADR scheme (CISAS or the Communications Ombudsman) after eight weeks if unresolved.
- Switching mid-contract via porting your number does not waive the ETF — you still owe it to the losing provider.
What an early termination fee is and why it exists
When you sign a mobile contract — whether for a SIM-only plan or a handset bundle — you commit to paying a monthly charge for a fixed term, typically 12 or 24 months. If you cancel before that term ends, your operator loses the revenue it expected. An early termination fee is a contractual mechanism to compensate the operator for some or all of that expected revenue. Under UK contract law and Ofcom’s General Conditions of Entitlement, however, that compensation must reflect actual loss, not function as a financial penalty designed to deter cancellation.
The distinction matters in practice. A genuine loss-based ETF decreases month by month as fewer payments remain outstanding and as any element of handset subsidy is recovered. A flat-rate cancellation charge or a fee that does not diminish over time would be far harder to justify under Ofcom’s framework and could also attract scrutiny under the Consumer Rights Act 2015, which prohibits unfair contract terms.
The Ofcom proportionality rule in detail
Ofcom’s General Condition C1 requires that any ETF be no higher than the sum of: (a) the remaining monthly subscription charges for the unexpired minimum period; minus (b) any cost savings the provider makes as a result of the early termination — for example, not having to provide the service for those remaining months, which may involve avoided wholesale or interconnect costs. In practice operators often describe this as “remaining line rental minus a discount for unprovided service costs.”
Ofcom published guidance making clear that ETFs must be clearly set out in pre-contract information, must be stated as a maximum figure that declines over time, and must be individually calculable at any given point in the contract. Operators are not permitted to bundle hidden charges into an ETF or to reclaim hardware costs already included in the monthly price through a separate termination levy. Where a handset is bundled into the contract price, the entire monthly payment — including the effective device instalment — may form part of the ETF calculation, but only up to the remaining months of the minimum term.
Step-by-step calculation method
To check whether the ETF you have been quoted is compliant, work through the following steps. First, establish how many months remain on your minimum term: if you are in month 18 of a 24-month contract, six monthly payments remain. Second, multiply that number of remaining months by your monthly subscription charge (the total amount billed each month, not just the headline tariff). Third, subtract any discount the operator applies for cost savings; this is typically a small percentage and operators should be able to state it clearly if you ask. The result is the maximum lawful ETF.
As a simplified illustration: six remaining months at £45 per month yields £270 before any deduction. If the operator applies a 5% cost-saving discount, the ETF would be £256.50. Any figure materially higher than this calculation — unless the operator can demonstrate specific additional recoverable costs permitted under the contract and consistent with Ofcom’s rules — warrants a formal challenge.
| Component | Operator may include? | Ofcom position |
|---|---|---|
| Remaining monthly subscription charges | Yes | Core of any ETF; must reduce month by month |
| Deduction for avoided service costs | Must deduct | Operator must subtract costs saved by not providing remaining service |
| Flat administration or cancellation fee | Not as an ETF uplift | Cannot inflate the ETF; may only be charged if separately disclosed pre-contract |
| Hardware cost already priced into monthly bill | Only as part of monthly charge sum | Cannot be charged twice; handset subsidy recovery is via remaining monthly payments |
| Future price-rise uplift | No | ETF is based on contracted charges, not hypothetical future increases |
Your right to price-rise cancellation without an ETF
Ofcom’s rules — updated and strengthened in 2023 — impose specific obligations on operators that raise prices mid-contract. Where a mid-contract price increase exceeds the rise permitted by the contract’s own terms, the customer must be given the right to exit without paying an ETF. Operators are required to notify customers at least 30 days before any such increase takes effect and to explain the right to cancel without penalty.
This is a separate right from the standard ETF framework. If your operator increased your monthly charge beyond the contractually permitted level and did not give you adequate notice or did not offer penalty-free exit, you may have grounds to leave without paying any ETF at all. Keep any notifications you received by text or email, as these are key evidence in any dispute.
How to check and challenge an ETF
Start by requesting a written breakdown of the ETF from your operator, specifying which monthly charge figure was used, how many months remain, and what cost-saving deduction was applied. Operators are obliged under Ofcom’s rules to provide this information clearly. Compare the stated ETF against your own calculation using the method above.
If the figures do not align, raise a formal complaint in writing with the operator, citing Ofcom’s General Condition C1 and stating the figure you consider to be the maximum lawful ETF. Operators have eight weeks to resolve complaints. If unresolved within eight weeks, or if you receive a deadlock letter, you may refer the dispute free of charge to the relevant approved ADR scheme — either CISAS or the Communications Ombudsman, depending on which scheme your operator belongs to. An ADR adjudicator can direct the operator to recalculate or refund an excess ETF.
ETFs and mid-contract switching
The One Touch Switch process introduced across the UK market allows consumers to switch mobile provider by agreeing terms with the gaining network, which coordinates the transfer. The switch does not cancel or waive any ETF owed to the losing provider. After porting your number, your former operator will issue a final bill that includes any outstanding ETF together with any partial-month charges for the service up to the switch date.
If you are switching because your current operator has raised prices in a way that triggers your right to exit without penalty, inform the losing operator of this before or at the point of switching. Document the basis for the penalty-free exit; if the operator then pursues an ETF regardless, the ADR route is available.
What this means in practice
Priya signed a 24-month contract in January 2025 at £38 per month, including a handset. In November 2025 — ten months in, with 14 months remaining — she wants to leave. Her operator quotes an ETF of £612. Priya calculates 14 × £38 = £532, before any cost-saving deduction. The quoted £612 is materially higher than the maximum permissible amount under Ofcom’s rules. She emails the operator asking for a written breakdown and citing General Condition C1. The operator acknowledges the error, revises the ETF to £508 (applying a small cost-saving adjustment), and Priya pays the corrected figure. No ADR referral was needed because the issue was caught early with a clear written challenge.
Related Guides
How we verified this
This article was researched using Ofcom’s General Conditions of Entitlement (specifically General Condition C1), Ofcom’s published guidance on mid-contract price rises and annual price increases (updated 2023), the Consumer Rights Act 2015 provisions on unfair contract terms, and Ofcom’s advice pages on cancellation and early exit fees on ofcom.org.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
How is a mobile early termination fee calculated?
Under Ofcom’s General Conditions, the ETF is calculated by multiplying your remaining monthly subscription charge by the number of months left in your minimum term, then subtracting any cost savings the operator makes by not providing the service for those months. The result is the maximum lawful charge. Any figure above this — such as a flat penalty fee or a charge for anticipated future price increases — would not comply with Ofcom’s rules.
Is there a limit on mobile early termination fees?
Yes. Ofcom’s General Condition C1 caps the ETF at the sum of remaining contracted monthly payments, minus the operator’s cost savings from not providing those months of service. Operators cannot charge more than this. The Consumer Rights Act 2015 also applies: a term imposing charges disproportionate to the operator’s actual loss is likely to be considered an unfair contract term and therefore unenforceable.
Can I challenge a mobile ETF?
Yes. Request a written breakdown from your operator showing the calculation. If the quoted ETF exceeds the maximum permitted under Ofcom’s rules, raise a formal written complaint citing General Condition C1. If the operator does not resolve the dispute within eight weeks, or issues a deadlock letter, you may refer the matter free of charge to the relevant approved ADR scheme — CISAS or the Communications Ombudsman — which has the power to direct a recalculation or refund.
What does Ofcom say about mobile ETFs?
Ofcom requires that ETFs be proportionate, transparent, and disclosed in pre-contract information. General Condition C1 specifically prohibits charges that exceed the operator’s genuine loss from early termination. Ofcom also requires operators to notify customers of any mid-contract price rises at least 30 days in advance and to give customers the right to exit without penalty where a rise exceeds the contractually permitted level.
Is the ETF based on remaining months?
Yes — the core of any compliant ETF is the number of months remaining in the minimum term multiplied by the monthly subscription charge. Because it is based on remaining months, the ETF must decline each month as the contract progresses. An ETF that does not reduce over time, or that is quoted as the same flat figure regardless of when you cancel, is unlikely to comply with Ofcom’s proportionality rules and should be challenged.
