Free cost comparison· UK figures
SIM-Free vs Contract Calculator
Your numbers, not the shop's: the phone outright plus a SIM-only plan against a phone-and-airtime contract, over the whole term, with the annual rises counted.
Data checked 26 September 2026· No sign-up · Feeds phones
The contract
Phone plus airtime, as the provider quotes it
The headline monthly figure, phone and airtime together.
Whatever is due on day one, often nothing.
Pounds added to the monthly price each year. Since 17 January 2025 the contract has to state this in pounds and pence.
SIM-free
Buy the phone, add a SIM-only plan
What the phone costs outright, from any shop.
A 30-day rolling or 12-month SIM-only plan with the data you need.
Many SIM-only plans rise too. Rolling plans can be swapped instead.
Result
The contract is cheaper by £62 over 24 months
Contract total
£978
£0 upfront + £978 airtime
SIM-free total
£1,040
£800 phone + £240 SIM-only
Difference
£62
in favour of the contract
Break-even SIM-only
£7.42/mo
the SIM-only price at which the two routes match
| Paid by end of | Contract | SIM-free |
|---|---|---|
| Year 1 | £480 | £920 |
| Year 2 | £978 | £1,040 |
Optional. You own the phone on both routes, so it cancels out unless one route locks you in longer.
- Since 17 January 2025 any mid-contract rise in a new UK phone contract must be printed in pounds and pence at the point of sale. Copy that figure into the annual rise field; it is added to the monthly price after each twelve months.
- UK providers have not been allowed to sell locked handsets since December 2021, so a contract phone can move to any network once the term ends.
- A 30-day rolling SIM-only plan can be swapped the moment a better deal appears. A contract cannot, which is worth something the sums do not capture.
Totals use 24 months. The break-even figure assumes the SIM-only plan rises at the rate entered above.
How it works
Method and assumptions
The calculator adds up what each route costs over the contract term. The contract route is the upfront payment plus every monthly payment; the SIM-free route is the handset price plus every monthly SIM-only payment. Both totals count the annual rise: since 17 January 2025 a UK phone or broadband contract has to state any mid-contract price rise in pounds and pence at the point of sale, so the figure you type in is the one printed in your contract, added to the monthly price after each twelve months.
The break-even figure is the SIM-only price at which the two routes would cost the same over the term. If you can find a SIM-only plan under it with the data you need, buying the phone outright wins on cost alone.
You own the phone at the end of either route, and handsets sold in the UK have had to be unlocked since December 2021, so resale value cancels out unless one route keeps you tied in for longer. The optional resale field is there for people who want to see the net figure anyway.
What the sums leave out: interest if the contract is structured as a separate credit agreement for the handset, cashback and trade-in offers, the value of a bundled extra such as a streaming subscription, and the fact that a 30-day rolling SIM can be swapped for a cheaper one the moment a better deal appears, which the contract route cannot do.
This is arithmetic on figures you enter, not financial advice. Offers change weekly and providers apply their rises on different dates; check the contract summary the provider must give you before signing, and read the credit agreement if the handset is financed separately.
SIM-free vs contract: Frequently Asked Questions
Is SIM-free cheaper than a contract?+
Usually, over the full term, if you compare like with like: the same phone bought outright plus a SIM-only plan with the same data allowance. Contracts spread the cost and sometimes bundle a discount on the handset, so the only honest answer comes from adding up both routes over 24 or 36 months, which is what the calculator does.
What does the annual rise field mean?+
Most UK contracts rise once a year, usually in the spring. For contracts taken out from 17 January 2025 the rise has to be stated in pounds and pence at the point of sale rather than as inflation plus a percentage, so copy the figure from the contract summary. Enter the monthly increase, not a yearly total.
Do I own the phone at the end of a contract?+
On a standard pay-monthly contract, yes, once the term ends, and since December 2021 handsets sold by UK providers have to be unlocked, so it can be used on any network. Some providers split the deal into an airtime plan and a separate handset credit agreement; check which you are being offered, because the credit agreement has its own terms.
Should I count the phone's resale value?+
Only if the two routes leave you with the phone at different times. If both end with you owning the same handset after the same number of months, the resale value is the same on both sides and cancels out. The field is there so you can see the net figure if you plan to sell.
What about a 36-month contract?+
A longer term lowers the monthly figure and raises the total, because there are more months of airtime and more annual rises to pay. Set the term to 36 months and compare: the SIM-free total also grows, since the SIM-only plan runs for the same 36 months, but a rolling SIM can be changed whenever a cheaper one appears.
Why does the calculator not show phone prices?+
Because the number that matters is the one you have been quoted, from whichever shop you are looking at, and Amazon only lets a site show its prices through its own price feed. Type in the price you can actually get and the calculator does the rest.
Ranked picks
Best SIM-free phones in the UK
If the sums favour buying outright, these are the phones we rank.
#1 Apple iPhone 17, 256GB, A19 chip, 120Hz ProMotion display, SIM-free and unlocked
Check price · premium
Check Price on Amazon →#2 Apple iPhone 16, 128GB, A18 chip, Camera Control, SIM-free and unlocked
Check price · premium
Check Price on Amazon →#3 Samsung Galaxy S25 Ultra, 256GB, 6.9-inch 120Hz, 200MP camera, SIM-free and unlocked
Check price · premium
Check Price on Amazon →Useful? Send it to whoever keeps asking.
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