Nothing Down, Plenty Owed: The Sum to Do Before You Say Yes to a Winter Upgrade
Every November, the same thing happens. Your network sends a cheerful text saying you're "eligible to upgrade", the shop window has a handset on a pedestal with the word FREE in letters the size of a bus, and somewhere in your head a small voice says: well, I'm paying the bill anyway.
That voice is the whole business model. The trick isn't lying to you — it's arranging the numbers so the handset disappears into a monthly figure you've already made peace with. So before you wander into a shop with your current phone in your pocket, let's pull the phone back out of the line rental and look at it on its own.
The word "free" is about timing, not price
A "free" handset almost never means zero pounds. It means zero pounds today. Everything after that is a repayment plan with a phone attached, dressed up as airtime.
Networks are not really doing anything sneaky here in a legal sense — the total is disclosed. It's just disclosed in a shape that's hard to feel. Forty-odd pounds a month for two years sounds like a phone bill. It is, in fact, a phone bill plus a small loan plus a service charge, welded together so you never see the seams.
Doing the sum properly
Here's the method. It takes about four minutes and a calculator.
- Take the monthly price and multiply it by the term length.
- Add any upfront payment.
- Look up what a SIM-only plan with a similar data allowance costs on the same network — typically £8–£15 a month in the current market.
- Multiply that SIM-only price by the same term length, and subtract it from your total.
What's left over is your handset cost. Compare that to the phone's outright retail price, and to what a refurbished or last-year's-model version sells for.
| 24-month deal | 36-month deal | |
|---|---|---|
| Monthly cost | £42 | £32 |
| Upfront | £0 | £0 |
| Total over term | £1,008 | £1,152 |
| SIM-only equivalent | £264 (£11 × 24) | £396 (£11 × 36) |
| Implied handset cost | £744 | £756 |
Both those numbers are in the region of full retail for a flagship handset — and in the 36-month case you're paying it off across three years, on a device you'll probably be itching to replace in two.
That's the comparison the poster never makes. The "free" phone is often the most expensive way to buy that phone, and it's certainly the least flexible.
The price rise that's now written in pounds
One genuinely useful change: since early 2025, Ofcom has required networks to state mid-contract price rises in pounds and pence, up front, rather than hiding behind an inflation figure plus a random percentage. That's a real improvement — but it doesn't make the rise disappear.
So do the boring thing. Find the sentence that says something like "your monthly charge will increase by £2.50 each April". Then add it up. A £2.50 rise landing from month 13 of a 24-month deal is £30 across the term. On a 36-month contract with two rises, you're looking at £75 or more. Not catastrophic. But it belongs in the total, not in the bin.
If the contract you're being offered still quotes an inflation-linked rise rather than a fixed figure, treat that as a yellow flag and ask for the number in pounds.
Your current phone is not worthless
Here's the bit that quietly changes the maths: the phone in your hand right now has a value, and trade-in offers are usually the lowest bidder in the room.
Before you accept whatever the shop offers, check what the same model fetches on a resale site, and what a refurbished unit sells for. The gap between a network trade-in quote and a private sale is frequently £80–£150 for a two-year-old handset in decent nick.
That gap is real money, and it's money you can put towards buying the new phone outright — which then frees you to take a cheap SIM-only deal and keep the flexibility.
The credit file footnote
Worth knowing: many handset contracts are split into an airtime plan and a device loan, and the device element can show up as credit on your file. That's not a problem in itself, but it does count when a lender looks at how much you've already committed to. If you're planning a mortgage application or a car finance agreement in the next year or so, a fresh 36-month device plan is a small but real addition to that picture.
The SIM-only alternative, plainly stated
Buy a handset outright — new, refurbished, or last year's model at a discount — and pair it with a SIM-only plan. You keep the phone, you keep the option to leave, and you can switch networks in minutes if a better deal appears. The upfront hit is bigger, which is exactly why the contract feels nicer. But you're paying for that comfort either way; the only question is whether you'd rather pay it in one go or in 36 instalments with a price rise attached.
If the upfront cost is genuinely out of reach, a 0% purchase credit card used carefully, or a smaller loan, is often cheaper than burying the handset in a tariff. Do the sum before you decide.
Three questions before you sign
Run these in the shop, out loud if it helps.
One: what's the total cost of this contract across the whole term, including every rise already written into it? If nobody can give you a single figure, that's your answer.
Two: what would this handset cost me outright, and what would my current phone fetch today? Subtract the second from the first. That's the real gap you're financing.
Three: will I still be happy with this phone in month 30 — and what does it cost me to leave if I'm not? Check the early exit charge. Then decide whether three years of commitment is a fair swap for a smaller number on the poster.
Upgrade season is designed to feel urgent. It isn't. Your current phone still works, the deals will still be there in a fortnight, and the maths doesn't change because the sign is red. Take the ten minutes. It's the cheapest part of the whole process.
