SIM-Free vs Contract: The Total-Cost Sums for UK Buyers

The honest way to compare

A phone contract is built to be judged by one number, the monthly figure, and that number tells you nothing on its own. The comparison that matters is the total over the term: for the contract, whatever you pay upfront plus every monthly payment until the minimum term ends, including the rise after each twelve months; for buying outright, the handset price plus the same number of months of a SIM-only plan with the data you actually use, plus any rise on that plan.

Whichever total is lower wins on cost alone. The SIM-free vs contract calculator does the adding up from the figures you have actually been quoted and gives you the break-even, the SIM-only price at which the two routes cost the same. Find a SIM-only plan below it with enough data and buying outright wins.

Compare like with like: the same storage, because none of the phones on our list can have it added later, the same data allowance and the same number of months.

The annual rise, and why it is now printed on the contract

Most UK contracts go up once a year, usually in the spring. Until recently the increase was inflation plus a percentage, unknowable on the day you signed. For contracts taken out from 17 January 2025, Ofcom requires any mid-contract rise to be set out in pounds and pence at the point of sale, and inflation-linked rises are banned in new contracts. Vodafone, for example, now states a fixed monthly increase on 1 April for its airtime plans, and says it does not apply to its device plans.

That figure belongs in your sum because you cannot use it to leave: Citizens Advice's guidance is that if the terms say the price can go up each year, a rise under that clause gives you no right to cancel without a fee. So copy the monthly increase from the contract summary into the calculator's annual rise field, as a monthly amount, not a yearly total.

Two ways a contract can be structured

The first is the traditional one: a single pay-monthly bill, handset and airtime folded into one price for a minimum term, usually 24 months and sometimes 36. Nothing falls away on its own when the term ends; your provider should remind you it is ending, and after that it is on you to move to SIM-only or a new deal.

The second splits the deal in two. Vodafone's EVO plans are the clearest example: a Phone Plan that is a Consumer Credit Agreement at 0% APR, spread over 24 to 36 months, and a separate Airtime Plan with its own Direct Debit, so two contracts and two payments a month. Once the phone is paid off, the airtime can move to a 30-day rolling plan.

The split matters most when you want to leave. On a single bill you are in for the term, and leaving early usually means an exit fee. With a credit agreement you can clear the handset early with extra payments, after which only the airtime ties you in, though leaving that inside its own minimum term usually still carries a fee. The credit agreement does not go away if you leave: you pay it off in full or keep paying it separately. Treat the handset price inside it as the number to set against the SIM-free price.

Unlocked, since December 2021

Locking used to be the quiet cost of a contract. Since December 2021, UK providers have not been allowed to sell locked handsets, so a contract phone moves to any network the day the term ends and its resale value matches a SIM-free one. Worth being straight about: the case for buying outright rests on the total and on flexibility, not on the lock.

What SIM-only buys you that a contract cannot

Leaving whenever a better deal appears. A 30-day rolling SIM can be swapped the moment a lower price for the same data turns up, and offers change weekly. A contract fixes one price, plus the printed rise, for the term. The calculator cannot count this.
Switching networks with one text. To keep your number, text PAC to 65075: the text is free, the code is valid for 30 days, and the new provider arranges the switch within one working day. Out of contract, that is the whole process.
Owning the phone from day one. If it breaks, is lost or you want the next one, there is no remaining term to clear first, and you can sell it whenever you like.

When a contract does win

Sometimes the total says so.

A genuine handset discount. Networks sometimes sell the phone for less inside a contract than outright. The sum finds this on its own: if the contract total comes in under the handset-plus-SIM-only total, the discount is real. If not, the advertised saving was the airtime.
Trade-in and cashback offers. The calculator leaves these out because they change weekly, so add them by hand: take a trade-in off the contract total if it only comes with the contract, and off the handset price if a maker or retailer will pay the same on a SIM-free purchase. Only the difference counts.
0% credit, if the alternative is paying interest. A handset credit agreement at 0% APR is an interest-free loan of the phone's price. If buying outright would mean carrying the balance on a credit card, the interest you would otherwise pay belongs in the sum. That is arithmetic, not financial advice; a decision that is really about borrowing belongs with someone who can see the rest of your finances.

The third route: refurbished, or last year's model

Buying outright opens a door the monthly figure hides. A refurbished handset from a business seller, with a stated warranty, goes into the calculator's handset field like any other price, and the Consumer Rights Act 2015 applies to goods sold by a trader. The other version is last year's model bought new: on our list the Apple iPhone 16 is the generation before the iPhone 17, costs less and still has years of Apple's support ahead of it, and the Samsung Galaxy S25 Ultra has been succeeded by the S26 Ultra and is the one with the deep owner record.

Which of our picks suits a SIM-free buyer

Every phone on our smartphones list is sold SIM-free and unlocked, so the question is which of them the outright route suits best.

The Apple iPhone 17 is the phone to buy outright if you keep phones for years: the newest Apple chip, the longest support runway on the list and 256GB as standard, per the listing. It is also the largest outlay of the iPhones here; the iPhone 16 gives up the 120Hz screen and half the storage for a lower price.

The Apple iPhone 16e is the smallest outlay onto Apple's current chip and full support period, with a single rear camera and no ultra-wide lens. If a contract tempts you because an iPhone in one payment feels like too much, this is the iPhone that makes the SIM-free sum easiest.

On Android, the Samsung Galaxy S25 is the strongest flagship for the money: the same chip as the S25 Ultra, 256GB as standard, a long published support commitment and a lower price than the iPhone 16. The S25 Ultra adds the 6.9-inch screen, the 200MP camera and the S Pen, with one SIM-free caveat: every Amazon UK listing is sold by a third-party seller, so check the returns terms before paying outright.

The Google Pixel 10 brings Google's camera processing and clean Android at a mid-range price, though the Galaxy S25 offers more storage and a better display for similar money. The Google Pixel 10a is the lowest outlay on the list with the longest promise attached: seven years of OS and security updates, per the listing, a quoted 30-hour battery and dispatch by Amazon. The best ratio of support years to outlay on the page.

Is SIM-free cheaper than a contract?

Usually, over the full term, if you compare like with like: the same phone outright plus a SIM-only plan with the same data, against the contract's upfront cost plus every monthly payment including the printed rise. Contracts sometimes carry a real handset discount, so the only answer that holds is the one you add up, which is what the calculator is for.

Do I own the phone at the end of a contract?

On a standard pay-monthly contract, yes, once the minimum term ends, and since December 2021 it will be unlocked. On a split deal you own the phone when the handset credit agreement is paid off, which you can do early; the airtime plan has its own term and carries on until you change or cancel it.

Can I get a contract phone unlocked?

If it was bought from a UK provider since December 2021 it should be unlocked already, because selling locked handsets has been banned since then. For an older handset, ask the network that sold it: for an iPhone, Apple says only the network provider can unlock it, and Settings, General, About shows "No SIM restrictions" against Network Provider Lock once it is.