SIM-only or a handset contract?

Compare buying a handset outright, financing one, taking a bundled contract, or keeping the phone you have — costed over the same period.

The period is the important one. Costing a two-year contract over two years hides what happens in year three, which is where buying outright usually wins.

Buying the handset
The bundled contract you are offered

Enter a SIM-only price and at least one way of getting a handset. Keeping the phone you have is always included as a fourth route.

Not enough to say anything yet

Low — this is a starting point, not a finding. More information would change it.

Nothing has been entered that can be turned into an answer. Every tool here works from figures you supply, and none of them will guess on your behalf.

What to try, all free

  1. Look up what you actually used

    Both Android and iOS keep a running total of mobile data, and your network shows the last few months in its app. That record beats every estimate on this page — use this tool to sanity-check it, not to replace it.

    • Do it now
    • Free

Worked out by mobile rules 1.0.0. Nothing you entered leaves your browser.

Why the usual comparison is not a comparison

“£45 a month with the phone, or £12 a month SIM-only” is not a choice between two prices. One of those includes several hundred pounds of handset and the other does not. Set side by side they make bundling look expensive and SIM-only look impossible, and neither impression survives working it out.

The only way to make them commensurable is to cost every route over the same number of months, including what the handset cost, what the finance added, and what the phone is worth at the end.

A lower monthly payment is not a lower total

This is the sentence the whole page exists for. Spreading a cost over more months reduces the payment and usually increases the total — that is what spreading a cost does. Where the cheapest route here has the highest monthly payment, the result says so explicitly, because that is the normal outcome and it is precisely the fact the monthly-price framing conceals.

Why the period matters more than the term

Costing a 24-month contract over 24 months hides what happens in month 25. A bundled contract that has finished paying for its handset does not get cheaper on its own — you keep paying the same amount unless you move — while somebody who bought outright has been on a SIM-only price the whole time and owns the phone.

So the question this tool asks first is how long you will actually keep the phone. If that is three or four years, which for most people it now is, the answer usually changes from what a two-year comparison would give you.

After a bundled term ends, this tool assumes you move to the SIM-only price you entered rather than staying on the bundled rate. That is the fair assumption, and it is also the thing a great many people never get round to doing — if you would not, the bundled route is worse than shown here rather than better.

Keeping the phone you have

Always one of the four routes, and usually the cheapest. A comparison that quietly left it out would be a shopping tool wearing a calculator’s clothes.

If the reason you are looking is that the current phone is failing rather than unfashionable, the repair or replace checkis the better starting point — a worn battery and a full storage drive both feel exactly like a phone at the end of its life, and both are cheap to fix.

Resale value, honestly

On the routes where you own the handset, what it is worth at the end comes straight off the cost, and that materially changes the ranking. On the route where you keep using your current phone, no resale is counted, because you still have it.

Resale figures are worth checking rather than guessing. They vary enormously by make, condition and how long you hold on — and a phone kept for four years is generally worth a small fraction of one kept for two.