In this guide
- Why SIM-only costs less than a handset contract
- When does switching to SIM-only make sense?
- What to check before switching
- What about annual price rises?
- FAQs
- How much can I save by switching to SIM-only?
- Do I need a new phone to switch to SIM-only?
- Can I get a good data allowance on a SIM-only plan?
- Editorial policy
If your phone contract has ended and you are still paying the same monthly amount, you are likely paying more than you need to. This guide explains how SIM-only deals compare on cost to handset contracts, when switching makes financial sense, and what to check before you move.
Reviewed by Phil Brown, founder of SIM Only Finder. Before launching SIM Only Finder, Phil worked in UK mobile retail at Three UK, advising customers on SIM plans, contracts, and network choices. He has spent over a decade running consumer comparison platforms. About the author
Last reviewed: March 2026.
Why SIM-only costs less than a handset contract
A pay monthly handset contract bundles the cost of the phone into your monthly bill alongside the network service. When you sign up, part of every monthly payment goes towards repaying the cost of the handset, and part goes towards your calls, texts, and data. The problem is that most networks do not automatically reduce your bill when the handset is paid off. If you do nothing at the end of your contract, you continue paying the same amount even though you are no longer paying for the phone.
A SIM-only deal separates the two. You pay only for the network service, with no handset cost included. According to Ofcom's research, customers who switch to SIM-only at the end of a handset contract can typically save between £10 and £20 per month compared to rolling onto the same deal.
You can compare current deals on our SIM-only deals page, where results are sorted by monthly cost and can be filtered by data allowance and contract length.
When does switching to SIM-only make sense?
Switching to SIM-only makes sense if your phone is in good working order and you do not need to upgrade. If you are happy with your current handset, paying for a new one through a bundle contract is an unnecessary cost.
It also makes sense if you want more flexibility. Most SIM-only deals are available on 30-day rolling contracts, which means you can switch to a better deal as soon as one becomes available without paying an exit fee. On a 24-month handset contract, leaving early usually means paying off the remaining months.
If you do want to upgrade your phone, buying a handset outright and pairing it with a SIM-only plan gives you more control over the total cost. You can choose when to buy, shop around for the best handset price, and keep your monthly network bill as low as possible.
What to check before switching
Before switching, check whether you are still within your minimum contract term. If you are, leaving early may incur an exit fee covering the remaining months. Most networks will tell you your contract end date in their app or by calling customer services.
Also check whether your phone is unlocked. Phones sold in the UK after December 2021 must be sold unlocked by law, but older phones may be locked to a specific network. If your phone is locked, you will need to request a free unlock from your current network before switching. See our guide on how to check if your phone is unlocked for step-by-step instructions.
You can keep your existing number when switching by requesting a PAC code. Text PAC to 65075 and you will receive your code within 60 seconds, free of charge. Give it to your new network when you sign up and your number transfers automatically. For full instructions, see our guide on how to keep your number when switching to SIM only.
What about annual price rises?
Most major networks apply annual price rises each April, including on SIM-only plans. If avoiding price rises is a priority, several networks have committed to no annual increases, including spusu and Lycamobile. On a 30-day rolling plan you are always free to leave if prices rise, which reduces the risk regardless of which network you choose.
For a full breakdown of which networks raise prices and by how much, see our guide to SIM-only mid-contract price rises.
FAQs
How much can I save by switching to SIM-only?
It depends on your current plan and what you switch to. As a general guide, SIM-only plans for moderate data usage (10 to 20GB) typically cost between £5 and £15 per month. If you are currently on a handset bundle paying £30 to £50 per month, the saving can be significant once the phone is paid off.
Do I need a new phone to switch to SIM-only?
No. You keep your existing phone and simply replace the SIM card. As long as your phone is unlocked and in working order, it will work with any SIM-only plan.
Can I get a good data allowance on a SIM-only plan?
Yes. SIM-only plans are available with data allowances from under 5GB up to unlimited. You can compare all options on our deals page, filtered by data allowance and monthly cost.
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