giffgaff SIM Only on 80GB (18 Month contract) with Unlimited mins…
80GBof 5G data
80 GBof 5G data
£10.00a month
No mid-contract price rise£0.00 upfront- No upfront cost
Buy nowat giffgaff
at giffgaffDeal details
Best SIM Only Deals UK
Already have a phone you love? Switch to SIM only, compare every UK network plan in one place, no hidden fees.
List of SIM-only deals (223)
223 deals · from 6 retailers · Updated 8h ago
18 month contract
£180.00 total cost
O2 SIM Only on Classic (24 Month contract) with Unlimited mins & texts…
Unlimited5G data
Unlimited5G data
£23.00a month
£0.00 upfrontNetwork offer: 3 months Free Disney+
- Unlimited data
- No upfront cost
Buy nowat O2 Mobiles
at O2 MobilesDeal details
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 upfrontEffective £5.10/mo- 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 upfrontEffective £5.61/mo- 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 upfrontEffective £5.50/mo- 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 upfrontEffective £6.13/mo- 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 upfrontEffective £6.64/mo- 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 upfrontEffective £7.00/mo- 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 upfrontEffective £7.15/mo- 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 upfrontEffective £7.50/mo- 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 upfrontEffective £7.66/mo- 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 upfrontEffective £8.17/mo- NEW
Buy 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 upfrontEffective £4.88/mo- 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 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
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
giffgaff SIM Only on goodybag 1GB with Unlimited mins & texts…
1GBof 5G data
1 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
Mozillion 10GB SIM, £6/mo, 24 months
10GBof 5G data
10 GBof 5G data
£6.00a month
£144.00 upfrontEffective £12.00/mo- NEW
Buy nowat Mozillion
at MozillionDeal details
iD Mobile SIM Only on 5G 25GB (1 Month contract) with Unlimited mins…
25GBof 5G data
25 GBof 5G data
£6.00a month
£0.00 upfront- No upfront cost
- 5G
- 1-month rolling
Buy nowat iD Mobile
at iD MobileDeal details
Smarty 18GB SIM, £6/mo with affiliate voucher, 1-month rolling
18GBof 5G data
18 GBof 5G data
£6.00a month
£6.00 upfront- 1-month rolling
- NEW
Buy nowat Smarty
at SmartyDeal details
iD Mobile SIM Only on 5G 12GB (12 Month contract) with Unlimited mins…
12GBof 5G data
12 GBof 5G data
£6.00a month
£0.00 upfront- No upfront cost
- 5G
Buy nowat iD Mobile
at iD MobileDeal details
iD Mobile SIM Only on 5G 15GB (24 Month contract) with Unlimited mins…
15GBof 5G data
15 GBof 5G data
£6.00a month
£0.00 upfront- No upfront cost
- 5G
Buy nowat iD Mobile
at iD MobileDeal details
iD Mobile SIM Only on 5G 15GB (1 Month contract) with Unlimited mins…
15GBof 5G data
15 GBof 5G data
£6.00a month
£0.00 upfront- No upfront cost
- 5G
- 1-month rolling
Buy nowat iD Mobile
at iD MobileDeal details
Showing 24 of 223 deals
The cheapest SIM only deal on SwitchSquid today (30 October 2026) is £2.50 a month for 10GB of data with Mozillion on a 24-month contract. We compare 223 SIM only deals and refresh prices from the providers’ feeds at least three times a day.
What Is a SIM Only Deal?
A SIM only deal gives you a monthly allowance of calls, texts and mobile data, without a phone included in the bundle. You pay for the SIM and the service, nothing else. Because networks are not subsidising the cost of a handset, monthly prices are significantly lower than phone contracts.
A SIM only deal is the right move if:
- You are happy with your current phone and do not want to upgrade
- You have just finished a phone contract and want to stop paying off a handset
- You have bought a phone outright or received one as a gift
- You want flexibility: 30-day rolling plans let you cancel any time with 30 days' notice
According to Ofcom research, buying a handset separately and pairing it with a SIM only plan is on average 23% cheaper than taking a combined handset-and-SIM contract. On a mid-range phone, that difference can be over £200 across 24 months.
Why Use Switch to Compare SIM Only Deals UK?
- We compare deals from EE, O2, Vodafone, Three, Giffgaff, Smarty, iD Mobile, VOXI, Lebara, Tesco Mobile, Sky Mobile and more
- Results are ranked by total monthly cost, not by commission rate
- Filter by network, data allowance, contract length, 5G, and roaming
- Free, independent and Ofcom-accredited
- Our team is reachable on 01926 942125 if you want a recommendation
Types of SIM Only Deals: Which One Is Right for You?
Choose the contract length that matches how you use your phone and how much flexibility you need.
1
30-Day Rolling Plans
The most flexible option. Cancel with 30 days' notice at any time. Monthly prices are slightly higher than 12-month contracts, but you are never locked in. Best for people who travel often, are mid-way through paying off a handset, or simply want freedom to switch the moment a better deal appears.
2
12-Month SIM Contracts
The most popular choice. Prices are lower than rolling plans, and deals are fixed for a year so you know exactly what you are paying. Best for people who are happy with their current network and want the lowest monthly cost without a long commitment.
3
24-Month SIM Only Deals
The cheapest per-month option, but you are tied in for two years. Some networks offer additional perks on 24-month plans, like extra data, inclusive roaming, and streaming subscriptions. Worth considering if you are very happy with your network and the saving is significant.
4
Pay As You Go (PAYG) SIM
No contract at all. Top up when you need to and pay for what you use. Best for very light users, people travelling short-term in the UK, or children's first phones. Not usually the best value for regular users who need data every month.
UK Mobile Networks: What You Need to Know
There are four main mobile networks in the UK: EE, O2, Vodafone and Three. Smaller providers (called MVNOs) run on these same masts and often charge less. Here is a quick comparison:
← Swipe to see all columns →
MVNOs use the same network infrastructure as their parent provider, so coverage is identical. The difference is price: MVNOs typically charge 20 to 40% less for similar data allowances because they have lower overheads.
How Much Data Do You Actually Need?
Most people overestimate how much data they use, and pay for data they never touch. Check your actual usage before you compare: iPhone: go to Settings, then Mobile Data, then scroll down to see monthly data used. Android: go to Settings, then Network, then Data Usage.
← Swipe to see all columns →
If you are frequently near the top of your allowance, go one tier up. Charges for exceeding your data allowance are expensive. Unlimited plans are often only a few pounds more than large data plans and remove the worry entirely.
How to Keep Your Number When You Switch SIM
You do not have to change your phone number when you switch networks. The process is simple and free:
1
Check You Are Out of Contract
Text INFO free to 85075 to confirm your contract status and whether any exit fees apply.
2
Request Your PAC Code
Text PAC free to 65075. You will receive your Porting Authorisation Code within 1 working day at no charge.
3
Compare and Sign Up
Use Switch to find your best SIM only deal. Select your new plan and complete the sign-up. No need to contact your current network.
4
Provide Your PAC Code and Transfer
Give your PAC code to the new network when signing up. Your number transfers automatically, usually within 1 working day. Your old contract cancels automatically. Important: do not cancel your old contract before getting your PAC code, you will lose your number permanently if you do.
eSIM: Do I Need a Physical SIM Card?
An eSIM is a digital SIM built into your phone. Instead of inserting a physical card, you download a profile from your new network. Most phones released since 2020 support eSIM, including all iPhones from the XS onwards and most Samsung Galaxy S and A series devices.
Benefits of eSIM:
- Instant activation: no waiting for a SIM card to arrive in the post
- Dual SIM capability on many phones: keep a personal and work number on one device
- No risk of losing or damaging a physical SIM card
Not all UK networks support eSIM on all plans, so Switch filters results to show you which deals are available as eSIM for your device.
SIM Only Deals with Roaming: What to Know
Roaming rules vary significantly between networks since the UK left the EU. Some networks include roaming in certain plans; others charge a daily fee. If you travel regularly, check roaming terms before you sign up. Always check the current terms on the network's site as these can change.
← Swipe to see all columns →
SIM Card Sizes: Which One Does Your Phone Take?
Most modern phones use a Nano SIM. Almost all networks send a 3-in-1 SIM (also called a multi-SIM or combi SIM) that includes all three sizes in one card, so you simply pop out the size you need. If you are not sure, check your phone's manual or the manufacturer's website.
← Swipe to see all columns →
Do SIM Only Deals Include 5G?
Yes. 5G is now standard on most SIM only plans from all four major UK networks, with no extra cost. As of 2026, Ofcom data shows that 85 to 93% of UK premises can receive outdoor 5G coverage from at least one network. Urban areas have the best coverage; rural areas are improving steadily.
To use 5G, your handset must be 5G-compatible. If your phone is 4G only, a 5G SIM will work perfectly: you will just connect at 4G speeds. You can check network 5G coverage at your home and workplace using the Ofcom coverage checker at checker.ofcom.org.uk.
How Much Can You Save With a SIM Only Deal?
The biggest saving comes when your phone contract ends and you stay on the same plan without switching to SIM only. At that point you are still paying the full monthly price, including a handset you have already paid off. Moving to a SIM only plan removes that cost immediately.
← Swipe to see all columns →
Compare SIM Only Deals UK: Free, Fast, Independent
Switch compares hundreds of sim only deals uk from every major network and MVNO in one place. Enter your data needs, choose your contract length, and see the cheapest options available right now, ranked by total monthly cost, not commission.
The comparison is completely free. There is no obligation to switch. If you want help choosing, our team is available on 01926 942125.
Ask Squid AI
Not sure how much data you need?
Ask Squid AI. Tell it your budget and how you use your phone, and it'll show SIM-only plans from our live list that fit.
Squid AI can make mistakes, so check the deal page before you buy.
FAQs
What is the difference between a SIM only deal and a phone contract?
A phone contract bundles a handset and a SIM together. You pay a monthly amount that covers both the phone cost and the airtime. A SIM only deal is just the airtime: calls, texts and data. Because there is no handset to pay off, monthly prices are much lower.
Can I keep my current phone number when I switch to a SIM only plan?
What happens to my current contract when I switch?
Are sim only deals uk available with 5G?
What is a 30-day rolling SIM deal?
What is an MVNO and should I consider one?
How do I know which network has the best coverage where I live?
Can I get a SIM only deal without a credit check?
What is an eSIM and do I need one?
How often should I compare SIM only deals?
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