Compare SIM-only deals in the UK
Last updated: 22 October 2026
Keep your phone and cut your bill. CompareDirect lists SIM-only plans from UK networks in one place, so you can compare data, monthly price and contract length directly — and go straight to the network to buy.
Why choose a SIM-only deal?
A SIM-only plan pays for calls, texts and data only — not for a handset. If your phone is paid off, or you bought it outright, a SIM-only deal is usually the cheapest way to stay connected in the UK.
Many plans are rolling 30-day contracts, so you can leave with a month's notice. Twelve- and twenty-four-month plans often cost less each month in return for staying longer.
How to compare SIM-only deals
Start with how much data you really use — your phone's settings show last month's usage. Then filter by network, data allowance and contract length, and sort by monthly price.
Check whether the price can rise during the contract. Since January 2025 UK networks must show any mid-contract rise in pounds and pence when you sign up.
Look at extras too: EU roaming, 5G access, Wi-Fi calling and data rollover can matter more than a £1 difference.
Keeping your number when you switch
Text PAC to 65075 to get your switching code free and instantly. Give it to your new network and your number moves over, normally within one working day.
Frequently asked questions
What is the cheapest SIM only deal in the UK?
It changes often. Open our SIM-only comparison and sort by price to see the lowest monthly plans in our latest dated snapshot, then confirm the price on the network's own site.
Can I use a SIM-only deal with any phone?
Yes, as long as your phone is unlocked or locked to the same network. Most phones sold in the UK since December 2021 are sold unlocked.
Is a 30-day SIM better than a 12-month SIM?
A 30-day SIM gives flexibility to leave any month. A 12-month SIM is often cheaper per month but ties you in for the year.
Will a SIM-only deal affect my credit score?
Pay-monthly plans normally involve a credit check. Pay-as-you-go SIMs don't. CompareDirect is not a credit broker and does not run credit checks.
How much data do I need?
Light users (messaging, maps) often manage with 5–10GB. Regular streaming or hotspotting typically needs 30GB or more, or unlimited data.
Read more
- Cheap SIM-only deals under £6
- Unlimited data SIM plans
- Our step-by-step sim-only deals buying guide
- Check mobile coverage before switching
- Compare phone deals
- Compare broadband deals
- Compare energy deals
- Compare car insurance
Listings are dated snapshots of providers' own pages (checked 22 October 2026), not live prices. CompareDirect is not a credit broker and gives no financial advice.