Cheap SIM-only deals in the UK
Last updated: 22 October 2026
A cheap SIM-only plan is the quickest way to cut a phone bill if your handset is paid off. We list the lowest-priced plans in our dated snapshot, cheapest first, so you can see what a few pounds a month actually buys before you decide.
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Cheap SIM-only deals under £6 a month
Advertised plans we hold in our dated snapshot, cheapest first (checked 22 October 2026). Prices exclude any mid-contract rises shown in the plan's own terms.
| SIM | Data | Monthly price | Contract length | Runs on |
|---|---|---|---|---|
| Sky Mobile | 1GB | £1.00/month | 24 months | O2 |
| Lycamobile | 5GB | £3.50/month | 30-day rolling | EE |
| RWG Mobile | 2GB | £3.50/month | 30-day rolling | EE |
| Talkmobile | 100GB | £4.98/month | 12 months | Vodafone |
| Lebara | 5GB | £5.00/month | 30-day rolling | Vodafone |
| 1pMobile | 5GB | £5.00/month | 30-day rolling | EE |
| Lycamobile | 30GB | £5.00/month | 30-day rolling | EE |
| ASDA Mobile | 3GB | £5.00/month | 30-day rolling | Vodafone |
| Talkmobile | 10GB | £5.95/month | 30-day rolling | Vodafone |
| Talkmobile | 150GB | £5.97/month | 12 months | Vodafone |
| SMARTY | 5GB | £6.00/month | 30-day rolling | Three |
| giffgaff | 2GB | £6.00/month | 30-day rolling | O2 |
| iD Mobile | 12GB | £6.00/month | 12 months | Three |
| Sky Mobile | 5GB | £6.00/month | 24 months | O2 |
Prices are advertised rates from each provider's own page on the date we checked, not live quotes. Clicking a name takes you to the provider.
How cheap can a SIM-only plan really be?
In our snapshot the cheapest rolling plans sit between £1 and £6 a month. At that price you are normally buying a small data allowance — 1GB to 5GB — with unlimited UK calls and texts, on a 30-day rolling contract.
A few networks also advertise very cheap 12 or 24-month SIMs with larger allowances. They cost less each month, but you are tied in, so check the early-exit terms before you commit.
What you give up at the lowest prices
Budget plans often use a smaller network's coverage footprint, may exclude EU roaming or cap it, and rarely include extras such as data rollover or priority customer service. Some cheapest-tier plans are 5G-ready but throttle speeds.
If you travel regularly or depend on signal at home, compare the network behind the plan rather than the price alone. Our SIM comparison shows which network each plan runs on.
Making a cheap SIM work for you
Check your real data use first: your phone's settings show last month's consumption, and most people use far less than they pay for. If you are on Wi-Fi at home and work, a 5GB plan is often enough.
Keep your number by texting PAC to 65075 — it is free and instant — then give the code to your new network. The move normally completes within one working day, and Ofcom rules mean you should not be charged for leaving.
Frequently asked questions
What is the cheapest SIM only deal in the UK?
It changes often. In our 22 October 2026 snapshot the lowest-priced rolling plans start around £1 to £3.50 a month for a small data allowance. Sort our SIM comparison by price and confirm the current price on the network's own page.
Is a £5 SIM worth it?
If you use under about 5GB of data a month and mostly call and text, yes — it is usually far cheaper than a mid-range plan. Check the coverage of the network behind it first.
Do cheap SIMs include calls and texts?
Most UK SIM-only plans include unlimited UK calls and texts whatever the price. International calls are usually charged separately or need an add-on.
Can I go back to my old network if a cheap SIM is no good?
Yes. On a 30-day rolling plan you can leave with notice and take your number with a PAC code. On a 12 or 24-month plan you may have to pay an early-exit charge.
Do cheap SIM-only plans need a credit check?
Rolling plans paid in advance normally do not. Contract plans usually do. CompareDirect is not a credit broker and runs no credit checks.
Keep comparing
Listings are dated snapshots of providers' own pages, not live prices, and CompareDirect does not sell the products we list. We are not a credit broker or lender and give no financial advice.