Handset Contracts vs SIM-Only: A 24-Month Cost Breakdown
Phone contracts are sold on monthly convenience, which makes them hard to compare properly against buying a handset outright and pairing it with a SIM-only plan. The only honest way to compare them is to add up the full 24 months, including the part most adverts don’t mention: the mid-contract price rise.
Why the Comparison Is Rarely Apples to Apples
Most major UK network contracts include an annual price increase tied to inflation, often described as CPI or RPI plus a fixed percentage. This means the monthly figure quoted when you sign up is not the figure you pay for the full term. A SIM-only plan bought separately, by contrast, is far more likely to have a fixed monthly price for its full term, because you’re not financing a handset through it.
To compare fairly, we need to build two full 24-month totals rather than just look at the headline monthly price.
Illustrative Scenario (figures for demonstration only)
Imagine a mid-range 24-month handset contract advertised at £45 a month. After 12 months, a typical mid-contract increase of around 8% applies, which is a plausible illustrative figure based on how these increases are commonly structured, not a quoted current rate.
| Route | Months 1-12 | Months 13-24 | 24-month total |
|---|---|---|---|
| Handset contract | £45.00 × 12 = £540.00 | £48.60 × 12 = £583.20 | £1,123.20 |
| Outright handset + SIM-only | Handset £699.00 upfront | £10.00 × 24 = £240.00 | £939.00 |
On these illustrative figures, buying outright and pairing with a SIM-only plan comes out roughly £184 cheaper over two years, purely because the handset-financing element of the contract carries the compounding price rise, while the SIM-only cost doesn’t.
Where the Maths Can Flip
This outcome isn’t universal. The comparison depends heavily on three variables:
- Handset price relative to contract subsidy. Flagship phones with steep RRPs sometimes get a genuinely better effective discount when bundled into a contract, especially during promotional periods.
- Whether the SIM-only deal is genuinely fixed-price. Some SIM-only plans also carry annual increases, which narrows or removes the gap entirely.
- How long you actually keep the handset. Buying outright only pays off if you keep using the same phone for the full term rather than upgrading early, since there’s no trade-in subsidy built in.
A contract locks you into the full term with an exit penalty if you leave early, usually calculated as the remaining airtime payments. Buying outright removes that penalty entirely: you can switch network or SIM provider the moment a better SIM-only deal appears, without owing anyone anything on the handset.
This flexibility has a value that’s easy to underrate. If your SIM-only provider puts prices up, or a better network deal appears, you can simply switch. On a handset contract, you’re generally stuck until the full term ends, even if the network’s own pricing becomes uncompetitive partway through.
Contracts described as offering a “free” or heavily discounted handset are, in reality, spreading the handset’s cost across the monthly payment. It’s worth checking whether the network publishes a separate “SIM-only equivalent” price for the same tariff, since the difference between that figure and the contract price is effectively what you’re paying to finance the device, often at an implied interest rate well above what a standard loan would charge.
Handset contracts sometimes bundle in device insurance or a damage protection add-on, either automatically or as a tempting optional extra at sign-up. This cover has a real monthly cost even when marketed as a small add-on, and it’s worth pricing separately against standalone gadget insurance, which is often available from specialist insurers at a lower monthly rate for comparable cover. If you’re buying outright, you have complete freedom to shop around for insurance separately, or to self-insure by setting aside the equivalent monthly amount, rather than being tied to whatever cover the network bundles in.
Whichever route you choose, the handset you’re replacing has some residual value, whether through a network’s trade-in scheme at the point of upgrade, or a private sale if you’re buying outright. Contract-linked trade-in schemes are convenient but don’t always offer the strongest price compared with a private sale or a specialist trade-in marketplace. If maximising value from your old handset matters, it’s worth checking both routes independently rather than assuming the network’s in-store trade-in offer is automatically the best available price on the day.
Data Allowance: Make Sure You’re Comparing Like for Like
None of the maths above means much if the SIM-only plan has noticeably less data, minutes or texts than the contract tariff it’s being compared against. Before running the 24-month totals, check both options offer a genuinely comparable allowance for your actual usage, since a cheaper SIM-only total that then forces you to buy a data top-up every month erodes the saving quickly, and sometimes removes it entirely.
A Simple Checklist Before You Choose
- Add up the full 24-month cost of the contract, factoring in the stated or likely annual price rise, not just month one.
- Check the current retail price of the handset you want, including any seasonal reductions, if buying outright.
- Compare that total against 24 months of a genuinely fixed-price SIM-only plan with similar data and minutes.
- Factor in how long you realistically plan to keep the handset before upgrading.
- Check the network’s early termination terms in case your circumstances change.
Who Each Route Actually Suits
Handset contracts tend to suit people who struggle to find several hundred pounds upfront, or who want the newest flagship device without saving for it first. Buying outright with SIM-only suits people with some savings to spare, who keep phones for longer than two years, or who want the freedom to switch network whenever a better deal appears.
Neither is objectively “correct” for everyone. The point of running the full 24-month maths yourself, rather than trusting the monthly headline figure, is that it reveals which option actually matches your situation rather than which one looks cheapest on a shop floor display.
Prices, price-rise formulas and SIM-only tariffs change regularly, so always check current terms directly with the network or retailer before committing. This article is for general guidance and is not financial advice.