Best SIM Only Deals UK 2026

Finding the best SIM only deals UK 2026 has never mattered more — because right now, the big networks are hiking bills faster than inflation, and millions of people are overpaying on contracts they don’t need. Research published by MoneySavingExpert in June 2026 found that 75% of mobile customers are worse off under Ofcom’s new fixed-rise system, with some networks raising bills by up to 13.4% — more than four times the 3.2% inflation rate. The good news? A growing list of MVNOs are holding the line on price rises, and you can get 30GB of data for as little as ~£8/mo (as of June 2026) on a no-contract, 30-day rolling plan. This guide covers the best deals across every category — budget, unlimited, 12-month contracts, international calls — and tells you exactly which networks won’t hike your bill mid-contract.

If you’re weighing up whether switching makes sense for you, our guide to SIM-only vs phone contract has the full breakdown. The short version: most people with a phone that’s more than 18 months old could save around ~£304/yr (source: Uswitch, June 2026) by switching to SIM-only.

Our top picks: best SIM only deals in June 2026

Here’s a quick at-a-glance comparison of the top deals we cover in this guide. Prices are as of June 2026 and are marked with ~ where they represent introductory or approximate rates.

Provider	Monthly price	Data	Contract	Network	Price rises?
Lebara	~£3.18/mo intro, then ~£7.95/mo	50GB	30-day rolling	Vodafone	No
SMARTY	~£8/mo	~30GB	30-day rolling	Three	No
iD Mobile	~£6/mo	25GB	30-day rolling	Three	No
iD Mobile	~£4/mo intro, then £8/mo	40GB	12-month	Three	No
VOXI	~£10/mo	80GB	30-day rolling	Vodafone	No
giffgaff	from ~£6/mo	Various	30-day rolling	O2	No
Talkmobile	~£8.95/mo	100GB	30-day rolling	Vodafone	No
Lycamobile	~£2.50/mo intro, then ~£5/mo	5GB	30-day rolling	Various	No

Quick verdict cards

Best SIM only deals under £10 a month

You don’t need to spend a lot to get a decent SIM. The sub-£10 market is packed with competitive offers from MVNOs who piggyback on the big four networks — meaning you get the same signal for less money. Here are the standouts.

Lebara 50GB — from ~£3.18/mo

Lebara is one of the most generous introductory offers on the market right now. You pay ~£3.18/mo for the first three months, then it rises to ~£7.95/mo on a 30-day rolling basis (as of June 2026, source: Uswitch). That’s 50GB of data on Vodafone’s network — perfectly adequate for streaming, social media, and everyday browsing. Lebara also includes international minutes to 100+ countries in every plan, which makes it a dual-purpose pick: budget and international at the same time. No credit check required, and no mid-contract price rises.

The main thing to watch: Lebara’s coverage is only as good as Vodafone’s in your area. Check the Vodafone coverage map before switching. The introductory price also runs out after three months, so set a calendar reminder to reassess if the jump to ~£7.95/mo doesn’t suit you — on a 30-day rolling plan, you can switch again without penalty.

Visit Lebara’s website to check current plans and introductory offers — deals can change week to week.

SMARTY ~30GB — ~£8/mo

SMARTY is owned by Three and runs on Three’s 5G network, which is the fastest in the UK by average 5G speed (~210 Mbps average, per Vertu/RootMetrics 2026 data). At ~£8/mo for around 30GB on a 30-day rolling plan (as of June 2026, source: Uswitch), this is one of the clearest value picks on this list. No price rises, no long-term commitment, and 5G included at no extra charge. SMARTY also offers data-only SIMs for tablets and hotspots.

One thing SMARTY doesn’t do is roaming in as many destinations as some rivals — worth checking if you travel frequently. But for a pure UK everyday SIM with solid coverage and no bill shock, it’s a top pick. SMARTY also has a “refer a friend” cashback scheme that can reduce your monthly cost further.

Check SMARTY’s current plans on their website — pricing is updated regularly and introductory deals come and go.

iD Mobile 25GB — ~£6/mo

iD Mobile is another Three MVNO with a strong reputation for flexible, low-cost plans. The 25GB plan at ~£6/mo (as of June 2026, source: Uswitch) is a 1-month rolling deal, meaning no long commitment. iD Mobile stands out for its data rollover feature: any data you don’t use in a month gets carried forward to the following month, so you’re not throwing away what you’ve paid for. EU roaming is included across around 30 destinations.

iD Mobile also frequently runs gift card promotions — check the current deal at time of purchase since these can add significant value to the 12-month contract versions (see the 12-month section below). Customer service gets reasonable reviews for an MVNO, and the app is straightforward for tracking usage.

Visit iD Mobile’s website to see their current promotional deals — gift card offers update frequently.

Best unlimited data SIM only deals

If you stream video, use mobile as your main hotspot, or simply don’t want to count gigabytes, an unlimited data SIM is worth the extra monthly cost. But “unlimited” doesn’t always mean the same thing — there are real differences between the networks. For a deeper look, our guide to the best SIM deals for heavy data users covers the fine print on throttling and fair-use policies.

iD Mobile Unlimited — ~£15/mo (30-day rolling)

For unlimited data on a no-commitment rolling plan, iD Mobile at ~£15/mo (as of June 2026, source: MoneySavingExpert) is the strongest all-round pick. You’re on Three’s network — the fastest average 5G in the UK at roughly 210 Mbps — with no fair-use throttling for personal use. Unlimited calls and texts are included. No mid-contract price rises. If you want a 12-month deal, iD Mobile’s unlimited plan drops to ~£8/mo for months 1–3, then £16/mo for the remaining nine months, and often includes a £30 gift card that brings the effective monthly cost down significantly.

This is the MVNO route to true unlimited: same Three signal as a direct Three contract, but typically cheaper. The trade-off is that priority may sit with direct Three customers during network congestion, though this is rarely noticeable in practice.

Check current iD Mobile unlimited plans on their website — gift card promotions update regularly.

Three Unlimited — from ~£18/mo

If you’d prefer a direct relationship with Three rather than an MVNO, Three’s own unlimited plans start from ~£18/mo (as of June 2026, source: Vertu.com). You get the same fast 5G network with no fair-use throttling for personal use — Three is genuinely generous on unlimited. The advantage of going direct: you’re first in line on the network, and Three’s roaming coverage spans over 70 destinations on most plans. However, Three does apply mid-contract price rises (£1.80–£2.30/mo depending on plan, from February 2026), so if price stability is your priority, the MVNO route is better.

Visit Three’s website for their current unlimited SIM plans and any active promotions.

EE Full Works Unlimited — ~£28.80/mo

EE is consistently rated one of the UK’s best networks for coverage, particularly in rural areas. Their Full Works unlimited plan runs at around ~£28.80/mo (discounted from £48, as of June 2026, source: TechRadar). You get 5G+, uncapped speeds, and EU roaming included at no extra charge. EE’s coverage map is broader than Three’s in many rural postcodes, making it a better choice if you live or work outside cities. The downside: EE applies a £2.50/mo mid-contract price rise from 31 March 2026 on plans taken out on or after July 2025. That’s an annual increase of £30 on top of your monthly cost — worth factoring into the comparison.

Visit EE’s website to check current unlimited SIM plans — promotional pricing is updated regularly.

Best 12-month SIM only contracts

A 12-month contract commits you for a year but usually rewards that commitment with a lower monthly price. It’s the sweet spot for most people: better value than 30-day rolling, more flexibility than a 24-month handset contract. The deals below include gift card promotions — which effectively reduce your monthly cost further when you factor in the voucher’s value across the contract length.

iD Mobile 40GB — equivalent ~£3.09/mo

This is arguably the best value 12-month SIM deal available in June 2026. The headline price is ~£4/mo for the first three months, then £8/mo for the remaining nine — but iD Mobile includes a £47 gift card, which when spread over the 12-month contract brings the effective monthly cost to around ~£3.09/mo (source: MoneySavingExpert, 30 June 2026). You get 40GB of data on Three’s network, data rollover, and no mid-contract price rises. If you’re looking for a set-and-forget plan that’s genuinely cheap, this is it.

The only caveat: gift card promotions change regularly. The deal above reflects pricing as of 30 June 2026 — check the current offer at the time you sign up, as the voucher amount may vary. The underlying plan structure (intro pricing then standard rate) is fairly consistent.

Visit iD Mobile’s website for current 12-month deals and gift card promotions.

O2 12-month — from ~£8/mo for 32GB

O2’s own 12-month SIM plans start from around ~£8/mo for 32GB, scaling up to ~£16/mo for 250GB (as of June 2026, source: MoneySuperMarket). Every O2 plan includes unlimited calls and texts and access to O2 Priority — a perks scheme with regular freebies, early access tickets, and discounts at various retailers. O2’s network piggybacks are giffgaff, Sky Mobile, and Tesco Mobile, so if you’d prefer a direct relationship with O2 rather than an MVNO, this is the route. The catch: O2 applies a £2.50/mo annual price rise each April, which on a 12-month contract means one increase during your term.

Check O2’s current SIM-only deals on their website for the latest pricing and promotions.

giffgaff Unlimited — ~£14/mo (18-month)

giffgaff’s unlimited plan sits at ~£14/mo on an 18-month contract (as of June 2026, source: MoneySavingExpert). It runs on O2’s network and covers 37 roaming destinations. giffgaff scores around 4.0/5 for customer service according to review data, which is solid for an MVNO. No mid-contract price rises. The 18-month commitment is longer than most people prefer, but the monthly cost is compelling if you’re confident you won’t need to switch. giffgaff also offers monthly “goodybags” on 30-day rolling plans from ~£6/mo, so there’s a full range of options depending on how much commitment you want.

Check giffgaff’s current goodybag options — 30-day and longer-term plans are available on their website.

Best SIM only deals for international calls

If you regularly call abroad — family back home, business contacts overseas, or frequent travel — a standard SIM plan can quietly rack up massive bills. These two providers are built around international calling and offer a genuinely different proposition from the mainstream MVNOs.

Lebara — from ~£5/mo, calls to 50+ countries

Lebara includes calls to 50+ countries in all its plans — not as an add-on, but as standard. Their 5GB plan starts from ~£5/mo (or as low as ~£4.50/mo on some promotional rates) on a 30-day rolling basis, with no credit check required (as of June 2026, source: lebara.co.uk). EU roaming is free, and India roaming is also free — the latter making it particularly popular with the UK’s large South Asian community. Lebara runs on Vodafone’s network, so coverage across the UK is strong. No mid-contract price rises.

The 50GB plan at ~£7.95/mo (after the introductory rate) is the better deal if you use data heavily, but even the 5GB entry plan is remarkably good value if your primary use case is international calls with some data on the side. There’s no contract, so you can switch if a better deal comes along.

Check Lebara’s current plans on their website — introductory pricing and data allocations update regularly.

Lycamobile — from ~£2.50/mo intro, calls to 70+ countries

Lycamobile takes the international angle even further, with minutes to 70+ countries included across its plans. Their 5GB plan sits at a promotional ~£2.50/mo for the first three months, then ~£5/mo standard (as of June 2026, source: lycamobile.co.uk and MoneySuperMarket). EU roaming is included, and Lycamobile is eSIM compatible — useful if you’ve just bought a newer handset and don’t need a physical SIM. The network parent varies by region, but Lycamobile has solid UK coverage for most postcodes.

Lycamobile’s app and customer service reviews are mixed — the plans are excellent value, but if you run into a problem, resolution can take longer than with a direct network operator. For straightforward usage — international calls plus some data — it’s a strong pick. For complex issues, factor in the limited support experience.

Visit Lycamobile’s website for current introductory offers and their full country list for included international minutes.

Price rises: which networks won’t hike your bill?

This is the most important section of this guide right now. New research from MoneySavingExpert (June 2026) found that 75% of mobile customers are worse off under Ofcom’s January 2025 rule change — which required networks to show price rises in pounds and pence rather than CPI percentage. In theory, this was more transparent. In practice, some networks have used it to lock in rises of up to 13.4% in 2026 — nearly four times the current 3.2% inflation rate.

Here’s the current picture for the main networks (as of June 2026):

Network	Mid-contract rise 2026	When applied
EE	£2.50/mo	31 March 2026 (plans from July 2025)
O2	Up to £2.50/mo	April 2026
Three	£1.80–£2.30/mo (by plan size)	February 2026 onwards
Vodafone	£1.50–£2.50/mo	Each April
Lebara	No mid-contract rises	—
SMARTY	No mid-contract rises	—
iD Mobile	No mid-contract rises	—
VOXI	No mid-contract rises	—
spusu	No mid-contract rises	—
giffgaff	No mid-contract rises	—
Talkmobile	No mid-contract rises	—

The no-rise networks — Lebara, SMARTY, iD Mobile, VOXI, spusu, giffgaff, and Talkmobile — are all MVNOs. This is not a coincidence. MVNOs compete primarily on price and value, so locking in price rises mid-contract would kill their business model. The big four (EE, O2, Three, Vodafone) have larger marketing budgets and rely on switching inertia to absorb customer dissatisfaction over bill increases.

The practical advice: if you’re on a 12-month contract with one of the big four, factor in the price rise when comparing total cost. A £10/mo plan that rises by £2.50/mo in month four costs you £110 over 12 months — not £120. An £8/mo MVNO plan with no rises costs £96. The MVNO wins by £14, even before accounting for the fact that MVNO headline rates are often already lower.

MVNO vs main network: same signal, lower bill?

An MVNO (Mobile Virtual Network Operator) is a company that buys wholesale access to one of the big four networks — EE, O2, Three, or Vodafone — and resells it under its own brand. You get the same signal towers. The only difference is the pricing, the customer service setup, and any extras the MVNO adds (or removes).

Here’s the full map of which MVNO runs on which parent network (as of June 2026):

MVNO	Parent network	Key feature
SMARTY	Three	30-day rolling, no price rises, true unlimited
iD Mobile	Three	Data rollover, flexible contracts, gift card deals
Honest Mobile	Three	Eco-focus, 1% for the Planet
giffgaff	O2	No credit check, monthly goodybags
Sky Mobile	O2	Data Piggybank rollover, 12-month minimum
Tesco Mobile	O2	Clubcard points, family plans
VOXI	Vodafone	Social/music streaming free, 30-day rolling
Lebara	Vodafone	International calls, no credit check
Talkmobile	Vodafone	Budget pricing, no price rises
spusu	EE	Low prices, transparent billing
1pMobile	EE	Ultra budget, pay-per-use

The key question most people ask: will I notice the difference between an MVNO and the parent network? In day-to-day use, the answer is almost always no. The signal, speed, and 5G access are identical — you’re on the same masts. Where you might notice a difference: during peak congestion, when some networks give priority to their own-brand customers over MVNO traffic. In practice, this rarely affects performance noticeably. Customer service is the more real difference — direct network customers generally get faster resolution for account issues.

For most people comparing value, an MVNO on the right parent network is the smarter choice. The savings are real, the signal is the same, and the no-price-rise guarantee from most MVNOs is increasingly hard to ignore as the big four continue annual hikes. If you also want to compare phone contracts alongside SIM-only, that comparison is worth doing before you commit.

How to switch to SIM-only and keep your number

Switching networks is straightforward. The whole process can be done in under 10 minutes if you know the steps. Here’s how to do it without losing your current number.

1. Get a PAC code from your current network. Text “PAC” to 65075 — your current provider must reply within 60 seconds with your Porting Authorisation Code. This is a free text, and the PAC is valid for 30 days.
2. Choose your new SIM deal. Use the comparison table at the top of this guide to pick your preferred plan. Make sure the network has good coverage in your area — check the provider’s coverage map using your postcode.
3. Order your new SIM. Sign up online and select “I want to keep my number.” You’ll need to enter your PAC code during the sign-up process. The SIM typically arrives within 1–3 working days.
4. Wait for the switch to happen. Your number transfers to the new network on the date you agreed during sign-up. It usually happens overnight. You may lose signal for a few hours during the switch.
5. Insert your new SIM and check it’s working. Make a test call and check your data connection. If everything’s working, you’re done. If not, contact your new network’s customer service — they have 24 hours to resolve porting issues.
6. Cancel your old contract if needed. If you were on a rolling plan, it cancels automatically when you port out. If you’re on a fixed contract, check your end date — leaving early may trigger an early-exit fee.

Frequently asked questions about SIM only deals UK

What is a SIM-only deal and how does it work?

A SIM-only deal gives you a SIM card with a set allowance of calls, texts, and data each month — without a handset bundled in. You use the phone you already own (or one you’ve bought separately) and pay a lower monthly cost because you’re not financing a new device. Plans run on either a 30-day rolling basis (no contract, leave any month) or a fixed 12- or 18-month contract. The main advantage over a full phone contract is cost: you can typically save ~£304/yr switching from a 24-month handset deal to a SIM-only plan on the same network (source: Uswitch, June 2026).

Which network has the best SIM only deals in the UK right now?

For overall value in June 2026, Three’s MVNO ecosystem — particularly SMARTY and iD Mobile — offers the best combination of price, data, and no price rises. SMARTY’s ~30GB plan at ~£8/mo on 30-day rolling is our top budget pick. For unlimited data, iD Mobile at ~£15/mo (30-day rolling) or ~£8/mo intro on a 12-month deal is hard to beat. If international calls matter to you, Lebara (Vodafone network) is the standout at ~£5/mo with minutes to 50+ countries included.

Is it better to get a 30-day rolling SIM or a 12-month contract?

A 30-day rolling plan gives you maximum flexibility — you can leave any month without penalty, which is ideal if you travel frequently, might upgrade your phone soon, or simply want to switch if a better deal comes along. A 12-month contract typically offers lower monthly costs — sometimes significantly lower when gift card promotions are included (iD Mobile 40GB works out to ~£3.09/mo effective cost on a 12-month deal vs ~£6/mo on 30-day rolling). Choose 30-day if flexibility matters; choose 12-month if you want to lock in a lower price and you’re confident in the network’s coverage for your area.

Which SIM-only networks do NOT raise prices mid-contract?

As of June 2026, the following networks have committed to no mid-contract price rises: Lebara, SMARTY, iD Mobile, VOXI, spusu, giffgaff, and Talkmobile. All are MVNOs. The big four — EE, O2, Three, and Vodafone — all apply annual mid-contract rises ranging from £1.50/mo to £2.50/mo. Under Ofcom’s January 2025 rule change, these rises must be stated in pounds and pence at sign-up, not as a CPI percentage. MoneySavingExpert research (June 2026) found that 75% of customers are worse off under this system than the old CPI approach, with some bills rising 13.4% in 2026.

What is the cheapest SIM-only deal in the UK right now?

As of June 2026, the cheapest introductory SIM deals include Lycamobile 5GB at ~£2.50/mo for the first 3 months (then ~£5/mo), Lebara 50GB at ~£3.18/mo for the first 3 months (then ~£7.95/mo), and iD Mobile 40GB at ~£4/mo for months 1–3 on a 12-month contract (with a £47 gift card that reduces effective cost further). For a reliable ongoing rate without an introductory catch, spusu’s 3GB plan at ~£3.90/mo on 30-day rolling (EE network) is worth considering. Always check current pricing at the provider’s website — deals change week to week.

How much data do I need on a SIM-only plan?

It depends on how you use your phone. Light users (mostly calls, texts, WhatsApp, and occasional Maps) typically use 3–5GB per month. Medium users (daily social media, some video streaming, working from the phone occasionally) use around 10–30GB per month. Heavy users (frequent video calls, Netflix or YouTube on mobile, using the phone as a hotspot for a laptop) use 30GB+ and may benefit from an unlimited plan. A rough rule: if you spend more than an hour a day watching video on mobile data, go unlimited. If you mostly connect to Wi-Fi at home and work, 10–20GB is likely more than enough.

Can I keep my phone number when switching to SIM-only?

Yes. You keep your number by requesting a PAC code from your current provider (text “PAC” to 65075 — it’s free and takes under 60 seconds). Give this code to your new provider during sign-up, and your number transfers across when the new SIM activates. The switch typically happens overnight. You may lose signal for a few hours during the transfer, but the number transfers without any action needed from your contacts. The PAC code is valid for 30 days, so you have time to find the best deal before committing.

What is an MVNO and is it as good as a main network?

An MVNO (Mobile Virtual Network Operator) is a brand that resells access to one of the big four UK networks — EE, O2, Three, or Vodafone — at lower prices. Examples include giffgaff (O2), SMARTY (Three), Lebara (Vodafone), and spusu (EE). In day-to-day use, you get the same signal and speeds as the parent network because you’re using the same masts. The differences are in pricing (MVNOs are usually cheaper), customer service (parent networks have larger support teams), and during peak congestion (some MVNOs have lower network priority). For most users, the price saving far outweighs any minor performance difference.

Is an eSIM better than a physical SIM?

An eSIM is a digital SIM built into your phone — no physical card needed. The practical advantages: you can activate a new plan instantly without waiting for a SIM to arrive in the post, and you can store multiple plans on one device (useful for travel). The main limitation is that not all networks support eSIM, and not all phones support it — eSIM is standard on iPhones from XS onwards, and most flagship Android phones from 2022 onwards. If your phone supports eSIM and you want to switch providers quickly, it’s a convenient option. For most everyday users, a physical SIM works perfectly well and gives you more network choice.

How much can I save by switching to SIM-only from a phone contract?

The average saving is around ~£304 per year (~£25/mo) switching from a typical 24-month phone contract to a SIM-only plan on the same or equivalent network (source: Uswitch, June 2026). The saving is largest when your current handset contract has ended — at that point you’ve paid off the phone, but many people stay on the same monthly cost without realising the handset component is still bundled in. If you’ve had the same phone for more than 18 months, the maths strongly favour switching. Use the comparison table at the top of this guide to find a plan that matches your current data usage at a lower monthly cost.

Closing disclosure: TheTechVector earns a commission if you sign up via affiliate links on this page, at no extra cost to you. SIM affiliate links are not yet active — we link direct to providers in the meantime. All prices were checked as of June 2026 and are subject to change. Always verify the current price at the provider’s website before signing up.