Sky Mobile 1GB SIM, £1/mo (£5 after 12 months), 24 months
1GBof 5G data
1 GBof 5G data
£1.00a month
£0.00 upfront- No upfront cost
Buy nowat Sky Mobile
at Sky MobileDeal details
Cheap SIM Only Deals UK
Compare cheap SIM only deals: calls, texts, and data only, no handset cost, no 24-month lock-in.
List of SIM-only deals (445)
445 deals · from 9 retailers · Updated just now
24 month contract
£1 a month on a 24-month contract, with price rises each year
Mozillion Pay Monthly Plus 10GB 24 months (£62.50 upfront + £2.50/mo)
10GBof 5G data
10 GBof 5G data
£2.50a month
£62.50 upfront- NEW
Buy nowat Mozillion
at MozillionDeal details
Mozillion Pay Monthly Plus 30GB 24 months (£68.75 upfront + £2.75/mo)
30GBof 5G data
30 GBof 5G data
£2.75a month
£68.75 upfront- NEW
Buy nowat Mozillion
at MozillionDeal details
Mozillion 1GB SIM Only, 12-month
1GBof 5G data
1 GBof 5G data
£2.75a month
£33.00 upfront- NEW
Buy nowat Mozillion
at MozillionDeal details
Mozillion 80GB SIM Only, 24-month
80GBof 5G data
80 GBof 5G data
£3.00a month
£75.00 upfront- NEW
Buy nowat Mozillion
at MozillionDeal details
Mozillion Pay Monthly Plus 100GB 24 months (£81.25 upfront + £3.25/mo)
100GBof 5G data
100 GBof 5G data
£3.25a month
£81.25 upfront- NEW
Buy nowat Mozillion
at MozillionDeal details
Mozillion 3GB SIM Only, 24-month
3GBof 5G data
3 GBof 5G data
£3.50a month
£84.00 upfront- NEW
Buy nowat Mozillion
at MozillionDeal details
Mozillion 210GB SIM Only, 24-month
210GBof 5G data
210 GBof 5G data
£3.50a month
£87.50 upfront- NEW
Buy nowat Mozillion
at MozillionDeal details
Mozillion 3GB SIM Only, 12-month
3GBof 5G data
3 GBof 5G data
£3.75a month
£45.00 upfront- NEW
Buy nowat Mozillion
at MozillionDeal details
Mozillion 260GB SIM Only, 24-month
260GBof 5G data
260 GBof 5G data
£3.75a month
£93.75 upfront- NEW
Buy nowat Mozillion
at MozillionDeal details
Mozillion Pay Monthly Plus 310GB 24 months (£100 upfront + £4/mo)
310GBof 5G data
310 GBof 5G data
£4.00a month
£100.00 upfront- NEW
Buy nowat Mozillion
at MozillionDeal details
Mozillion 30GB PAYG 24 months (£4/mo)
30GBof 5G data
30 GBof 5G data
£4.00a month
£96.00 upfrontBuy nowat Mozillion
at MozillionDeal details
Mozillion 3GB SIM, £4.50/mo, 1-month rolling
3GBof 5G data
3 GBof 5G data
£4.50a month
£4.50 upfront- 1-month rolling
- NEW
Buy nowat Mozillion
at MozillionDeal details
Lebara 5GB SIM, £4.50/mo, 12 months
5GBof 5G data
5 GBof 5G data
£4.50a month
No mid-contract price rise£4.50 upfront- NEW
Buy nowat Lebara
at LebaraDeal details
Lebara 5GB SIM, £5/mo, 1-month rolling
5GBof 5G data
5 GBof 5G data
£5.00a month
No mid-contract price rise£5.00 upfront- 1-month rolling
- NEW
Buy nowat Lebara
at LebaraDeal details
Mozillion 100GB PAYG 24 months (£5/mo)
100GBof 5G data
100 GBof 5G data
£5.00a month
£120.00 upfrontBuy nowat Mozillion
at MozillionDeal details
Sky Mobile 10GB SIM, £5/mo, 24 months
10GBof 5G data
10 GBof 5G data
£5.00a month
£0.00 upfront- No upfront cost
Buy nowat Sky Mobile
at Sky MobileDeal details
Sky Mobile 100MB SIM, £5/mo, 24 months
0.1GBof 5G data
0.1 GBof 5G data
£5.00a month
£0.00 upfront- No upfront cost
Buy nowat Sky Mobile
at Sky MobileDeal details
12 month SIM only contract - Unlimited Minutes & Texts plus 3GB Data
3GBof 5G data
3 GBof 5G data
£5.00a month
£5.00 upfront- NEW
Buy nowat Asda Mobile
at Asda MobileDeal details
24 month SIM only contract - Unlimited Minutes & Texts plus 3GB Data
3GBof 5G data
3 GBof 5G data
£5.00a month
£5.00 upfront- NEW
Buy nowat Asda Mobile
at Asda MobileDeal details
Mozillion 10GB SIM, £5.90/mo, 1-month rolling
10GBof 5G data
10 GBof 5G data
£5.90a month
£5.90 upfront- 1-month rolling
- NEW
Buy nowat Mozillion
at MozillionDeal details
12 month SIM only contract - Unlimited Minutes & Texts plus 10GB Data
10GBof 5G data
10 GBof 5G data
£5.95a month
£5.95 upfront- NEW
Buy nowat Asda Mobile
at Asda MobileDeal details
24 month SIM only contract - Unlimited Minutes & Texts plus 10GB Data
10GBof 5G data
10 GBof 5G data
£5.95a month
£5.95 upfront- NEW
Buy nowat Asda Mobile
at Asda MobileDeal details
giffgaff SIM Only on golden goodybag with Unlimited mins & texts…
2GBof 5G data
2 GBof 5G data
£6.00a month
No mid-contract price rise£0.00 upfront- No upfront cost
- No contract
Buy nowat giffgaff
at giffgaffDeal details
Showing 24 of 445 deals
What Is a SIM Only Deal?
A SIM only deal gives you a monthly allowance of minutes, texts, and mobile data on a SIM card, without a phone bundled in. The network is not subsidising any handset, so the monthly price is much lower than a standard phone contract.
SIM only suits you if you already own a smartphone, if you have bought a phone outright, or if your current handset contract has ended and you want to stop paying the device repayment element you no longer owe.
SIM Only vs Phone Contract: Quick Comparison
Switching from a 24-month handset contract to a SIM only deal when your phone is paid off could save you over £300 per year for the same data allowance.
← Swipe to see all columns →
How Much Can I Save With a Cheap SIM Only Deal?
When a 24-month phone contract ends, many people keep paying the same monthly amount, which still includes a device repayment for a phone already fully paid off. Switching removes that element immediately.
← Swipe to see all columns →
Figures are indicative ranges based on May 2026 market pricing. Actual deals vary by network and promotional period.
Types of Cheap SIM Only Deals
30-Day Rolling SIM Deals: A 30-day rolling SIM deal renews every month. You can cancel at any point, usually with 30 days notice. This is the most flexible option, ideal if you think your data needs might change, if you are between contracts, or if you simply do not want to commit long-term. The monthly price is usually slightly higher than a 12-month deal for the same data.
12-Month SIM Deals: A 12-month SIM deal locks you in for a year in exchange for a lower monthly price. For most people this is the right balance, you get the savings of a fixed term without the 24-month commitment of a phone contract. At the end of the 12 months, you are free to compare again and switch to an even cheaper deal.
No-Contract SIM Deals: Some providers, mostly MVNOs, offer truly contract-free SIM deals where you pay upfront each month and can stop at any time. These are great for people who want maximum freedom or who have a limited or no credit history, as many do not require a credit check.
Unlimited Data SIM Deals: Unlimited data SIM deals are now available from every major UK network and from many budget MVNOs. Prices have dropped significantly, you can find unlimited data SIM only plans for as little as £12 to £20 per month in 2026. If you stream video, work remotely, or use mobile data as a home broadband backup, unlimited SIM deals are worth comparing.
Which Networks Offer Cheap SIM Only Deals in the UK?
There are four main UK mobile networks, O2, Vodafone, Three, and EE, plus a range of budget MVNOs (Mobile Virtual Network Operators) that use those same masts at lower prices.
- O2: Wide 4G coverage and strong 5G rollout. Plans often include O2 Priority perks. 30-day and 12-month options available.
- Vodafone: Good UK and international coverage. Entertainment add-ons (Spotify, YouTube Premium) available on some plans.
- Three: Consistently strong 5G speeds. No annual price rises on SIM only plans. Roaming included in many deals.
- EE: Widest UK mobile coverage overall. Some plans come with extras such as Apple TV+ or Amazon Prime.
When comparing cheap SIM only deals UK buyers often find the best value comes from MVNOs rather than the major networks directly, same underlying coverage, lower monthly cost.
Budget MVNOs: Often the Cheapest SIM Only Option
MVNOs use one of the four main networks infrastructure and sell plans at lower prices due to lower overheads. Coverage is identical to the parent network.
← Swipe to see all columns →
How to Find the Cheapest SIM Only Deal: Step by Step
Five steps from checking your usage to your new SIM being active.
1
Check Your Actual Data Usage
Before comparing, find out how much data you actually use each month. On iPhone go to Settings then Mobile Data. On Android go to Settings then Network then Data Usage. Look at your last three months and pick the highest figure. Round up slightly so you do not run over your allowance every month.
2
Decide on Contract Length
30-day rolling gives you flexibility to switch whenever a better deal appears. 12-month gives you a lower monthly price. If you are fairly settled in your usage and network preference, 12-month typically gives you the best value on cheap SIM only deals in the UK.
3
Check Coverage in Your Area
A cheap SIM only deal on a network with poor signal where you live is not a deal at all. Use Ofcom's online coverage checker or the network's own coverage map before signing up. If only one network covers your area well, focus your comparison on that network's direct plans and any MVNOs that run on the same infrastructure.
4
Compare on Switch
Enter your data requirement and preferred contract length on Switch. Results show every available plan sorted by price, not by commission. You can filter by network, data allowance, contract length, 5G availability, and roaming. Every deal shows the full monthly cost with no hidden extras.
5
Get Your PAC Code Before You Switch
If you want to keep your existing mobile number, text PAC to 65075 (free). You will receive your PAC code within one working day by text. Give this code to your new provider when signing up. Your number will transfer automatically within one working day, with only a few minutes of downtime.
What to Watch Out for When Comparing Cheap SIM Deals
Four hidden costs and conditions that can turn a cheap deal into an expensive one.
1
Annual Price Rises
Some networks increase prices mid-contract each April, linked to inflation (CPI or RPI plus a fixed percentage). This can add several pounds per month to a deal you thought was fixed. Check whether a plan has annual price rises before signing up. Several MVNOs, including iD Mobile and Smarty, commit to no mid-contract price rises on SIM only deals.
2
Speed Caps
A small number of very cheap SIM plans apply a speed cap, limiting your download speeds to a slower rate even when you have data remaining. This may be fine for social media browsing but can cause problems if you stream video or use mobile data for work. Check the small print.
3
Introductory Pricing
Some plans offer a very low price for the first three to six months, then jump to a higher rate. The total cost over 12 months is what matters, not the headline monthly figure. When comparing deals on Switch, we show the full 12-month cost so you can compare like for like.
4
Data Rollover
Some networks and MVNOs let you roll unused data into the following month. If you are a variable user, heavy one month and light the next, data rollover means you are less likely to pay for data you never use. Look for this feature when comparing similar-priced plans.
eSIM vs Physical SIM: What You Need to Know
Most modern smartphones (iPhone XS onwards, recent Android flagships) support eSIM, a digital SIM built into the phone. With an eSIM you do not need to wait for a physical card to arrive. Your new plan activates via a QR code sent by email, usually within minutes of signing up.
If you prefer, you can still choose a physical nano SIM card. Most networks send these free by Royal Mail within two to three working days. Some networks send a three-in-one SIM card (standard, micro, and nano in one card) so you can pop out the correct size.
If you have an older phone that only takes a physical SIM, do not worry, every network still supports physical SIM cards. The comparison and switching process is exactly the same.
EU and International Roaming on Cheap SIM Deals
If you travel, roaming capability matters. Not all cheap SIM only deals include EU roaming, and on those that do, the terms vary.
- Three: includes roaming in many European and international destinations on most plans at no extra cost.
- O2: includes EU roaming on most pay-monthly plans.
- Vodafone and EE: offer EU roaming on selected plans, with add-on packs available for others.
- iD Mobile: includes roaming in 50+ destinations.
- Tesco Mobile: has committed to no EU roaming charges on their plans.
If you travel frequently, filter specifically for plans with inclusive roaming when comparing on Switch. Do not assume roaming is included just because a plan is from a major network.
Can I Keep My Number When I Switch SIM?
Yes. Keeping your mobile number when switching to a new SIM only deal is straightforward and free. Here is how it works:
- Text PAC to 65075 (free). You receive your PAC code within one working day.
- Sign up to your chosen SIM only deal on Switch and provide your PAC code during the process.
- Your number transfers automatically, typically within one working day.
- There is usually only a few minutes of downtime during the actual transfer.
- Your old contract is cancelled automatically once the PAC code is used. You do not need to contact your old network separately.
If you do not want to keep your number, simply sign up to a new deal without providing a PAC code. You will be given a new number with your new SIM.
Compare Cheap SIM Only Deals UK: Takes 2 Minutes
If you have not compared your mobile plan in the last 12 months, you are almost certainly overpaying. The cheap SIM only deals UK market has never been more competitive, prices have dropped and data allowances have grown. There is no paperwork, no engineer visit, and switching takes a few minutes online.
Switch compares every available SIM only deal by total monthly cost, no ranked-by-commission results, no cached pricing. Compare today, find your cheapest plan, and switch in minutes.
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FAQs
What is the cheapest SIM only deal in the UK right now?
The cheapest SIM only deals in the UK start from around £1 to £5 per month for low data allowances (1GB to 5GB), typically from MVNOs such as Lebara, Giffgaff, or Smarty. Prices change frequently, so compare live on Switch to see the cheapest available deal for your data amount today.
Is a SIM only deal better than a phone contract?
Can I get a SIM only deal with no credit check?
What is an MVNO?
Can I switch SIM deals without changing my number?
What happens to unused data on a SIM only deal?
Can I get a cheap SIM only deal with 5G?
What is a PAC code and how do I get one?
How long does it take to switch SIM?
Are there any SIM only deals without annual price rises?
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