Finding a decent SIM only deal in the UK shouldn’t feel like a part-time job. Between EE, O2, Vodafone, Three, and the dozen-plus virtual networks riding on their infrastructure, there are hundreds of live offers at any given moment — and most of them are buried across separate provider websites that all claim to be “the cheapest.” That’s exactly the mess Olimit was built to clean up.

Olimit has become one of the fastest-growing SIM and mobile comparison sites in the UK by doing one thing well: pulling every major network’s live deals into a single, filterable, no-nonsense comparison page — updated daily, with total cost shown upfront and zero pay-to-rank listings. Whether you want a 30-day rolling SIM, a 12-month contract, an unlimited data plan, a travel eSIM, or a new pay-monthly phone, Olimit is quickly becoming the first stop for UK consumers who are done overpaying for the same signal.

Every UK Network, One Comparison Table

The UK mobile market isn’t just four networks. It’s four networks — EE, Vodafone, O2 and Three — plus a long list of MVNOs (Mobile Virtual Network Operators) that lease capacity from those four and resell it, often much cheaper, under their own brand. Olimit tracks all of them:

Runs on EE: Lyca Mobile, 1p Mobile, Mozillion Runs on Vodafone: Lebara, Talkmobile, VOXI, Asda Mobile Runs on Three: iD Mobile, SMARTY

This distinction matters more than most people realise. An MVNO SIM on Lyca or 1p Mobile connects to the exact same masts as an EE SIM only plan — you get EE’s coverage and EE’s speeds, just without paying EE’s brand premium. Olimit makes this relationship explicit on every listing, tagging each deal with “Runs on EE,” “Runs on Vodafone,” or “Runs on Three,” so you always know exactly whose network you’re actually buying into before you check out.

SIM Only Deals by Network

Olimit maintains dedicated, constantly refreshed comparison pages for each network and MVNO, including:

Each network page breaks down what makes that provider stand out. Three, for instance, is positioned around generous data allowances at competitive prices, extensive 3G/4G/5G coverage, and unlimited calls and texts included as standard across its SIM Only range. O2’s pages highlight that SIM only plans are generally cheaper than bundled contracts since you’re not paying off a handset — a simple point that’s easy to forget when you’re staring at a flashy phone-plus-SIM bundle.

SIM Deals by Type, Not Just by Network

Not everyone wants the same kind of plan, and Olimit’s filtering reflects that. Instead of forcing you to hunt through generic “SIM deals” pages, it splits offers into the categories people actually search for:

Unlimited data SIM deals — from roughly £9/month, for anyone who streams, hotspots, or works from their phone constantly
30-day rolling SIM deals — flexible, cancel-anytime SIMs from as little as £1.49, ideal for expats, digital nomads, or anyone testing a network before committing
12-month SIM Only plans — a middle ground between flexibility and long-term savings
eSIM deals — instant, contract-free digital SIMs that activate via QR code in minutes
No credit check SIM deals — perfect for students, new UK arrivals, or anyone without a long UK credit history
International SIMs with UK, Europe, USA, India and China roaming — built specifically for travellers and frequent flyers
Tourist eSIMs for the UK — for visitors who want data the moment they land, with no UK address or bank account required

This is where Olimit separates itself from a generic price-comparison table. Every SIM listing is tagged with the details that actually change your decision: whether it’s eSIM-ready, whether it includes a credit check, how much roaming data it includes and where, and what the true total cost looks like across the full contract length — not just the monthly headline price.

Unlimited Data Without the Guesswork

Unlimited plans sound simple until you read the small print. Olimit’s own unlimited data guide points out something worth repeating: most UK unlimited data SIMs still cap how much of that data you can actually use abroad, typically somewhere between 12GB and 35GB a month once you’re roaming in the EU, and some networks charge extra for roaming destinations outside Europe entirely. Rather than leaving you to dig through each provider’s terms and conditions, Olimit flags the roaming allowance directly on the deal card, so a £9/month unlimited SIM that only gives you 15GB in Spain isn’t mistaken for one that gives you 35GB.

The site also tracks real-world network performance rather than just marketing claims — noting, for example, that Lyca (on the EE network) and Three tend to deliver some of the fastest real-world 5G speeds, reaching up to 400–500 Mbps in tested areas. That kind of detail is exactly why people increasingly treat Olimit as more than a price list — it functions as a genuine buying guide.

Roaming Deals That Actually Make Sense for Europe and Beyond

If you travel even occasionally, this is the section of Olimit worth bookmarking. The UK & Europe SIMs with global roaming hub is filterable by exact roaming destination — Europe, USA, India, or China — plus data amount, contract length, and price, so you’re not wading through domestic-only deals to find one that works in Faro or Frankfurt.

A few real examples currently live on the site show exactly why this page has become so popular:

Lebara SIM Only (runs on Vodafone) — 5GB of 5G data for £1.49 across the first three months (then £5), with no fixed contract, and roaming included across 37 destinations covering nearly the entire EU plus Iceland, Norway, Gibraltar, and India.
Mozillion SIM Only (runs on EE) — even the entry-level 1GB plan comes with roaming across a remarkable 41 destinations, stretching from mainland Europe to Switzerland, the Faroe Islands, San Marino, and the Channel Islands.
Lyca Mobile (runs on EE) — a 5GB, no-contract SIM at £2.50/month with roaming across 30 European destinations, plus 100 international minutes bundled in for calling home.

The takeaway is simple: some of the cheapest MVNO SIMs on the UK market — the ones running quietly on EE and Vodafone’s networks — now come with roaming allowances that comfortably rival flagship-network plans costing several times more. Olimit is one of the few UK comparison sites laying that pattern out in plain sight, rather than leaving travellers to work it out deal-by-deal.

eSIM: The Fastest Way to Get Connected

Physical SIM delivery can take days. Olimit’s eSIM comparison page exists for people who don’t want to wait — and it doesn’t just list deals, it explains the real trade-offs. As the site notes, an eSIM is especially useful because there’s no need to wait for delivery or fumble with a tray — you can switch networks instantly, store multiple digital profiles, and manage everything through your phone’s settings, which makes it a natural fit for frequent travellers and anyone juggling a personal and work number on one handset.

Olimit even shares real customer examples to illustrate the savings: one user activated an 80GB VOXI eSIM through Olimit for £10 — the same amount of data would have cost over £17 elsewhere, and they were connected within five minutes while friends elsewhere were still waiting for a physical SIM to arrive in the post. That’s the kind of concrete, provider-verified detail that turns a comparison table into something people actually trust.

Not Just SIMs: Phones Too

Olimit’s comparison engine extends beyond SIM Only plans into pay-monthly phone deals. Every current flagship is tracked — iPhone 17, iPhone 17 Pro Max, iPhone Air, Samsung Galaxy S26 and S26 Ultra, Google Pixel 10 and 10 Pro — alongside mid-range and budget picks from Motorola, Honor, OPPO, HMD, and Doro. Crucially, every phone listing shows the total contract cost — monthly price multiplied by contract length, plus any upfront payment — rather than just the monthly figure that makes a deal look artificially cheap.

Switching Is Easier Than People Think

One of the biggest reasons people stay on an overpriced plan is simply not knowing how switching works. Olimit’s guides break the process down into three steps that apply across virtually every UK network:

Compare and choose your new SIM Only deal using Olimit’s filters for data, price, and contract length.
Request your PAC code to keep your existing number — just text PAC to 65075 and your current network must send the code instantly, free of charge, and it works across all major UK networks.
Hand your PAC code to your new network when you sign up, and your number transfers automatically, usually within one working day.

By law, your current provider has to send that PAC code within two hours, and porting the number over typically completes the same day or the next.

No Credit Check? No Problem

Not everyone has a long UK credit history — international students, recent movers, and younger customers often get quoted worse deals or rejected outright by mainstream networks. Olimit’s no credit check SIM Only section filters specifically for providers that don’t run a hard credit check, making it one of the more genuinely useful corners of the site for people who’d otherwise be stuck overpaying or getting turned away.

Frequently Asked Questions About UK SIM Only Deals

Is Olimit actually free to use? Yes. Olimit is a comparison service, not a network — it earns a small commission if you buy through one of its links, but this never changes the price you pay or where a deal ranks. You’d pay exactly the same price buying directly from the network.

What does “runs on EE” or “runs on Vodafone” mean? Several UK networks — including iD Mobile, VOXI, SMARTY, Lyca Mobile, and Lebara — are MVNOs. They don’t own physical masts; instead, they lease network capacity from one of the big four and resell it under their own brand, usually at a lower price. You get the same underlying coverage and speed as the host network, just at MVNO pricing.

Should I choose SIM Only or a pay-monthly phone contract? If your current phone still works, a SIM Only plan is almost always the cheaper route, since there’s no handset cost baked into the monthly price. A pay-monthly phone contract makes more sense if you need a new device and don’t want to pay for it outright.

Can I keep my phone number when I switch networks with Olimit? Yes. Text PAC to 65075 from your current phone, and your network is legally required to send you a PAC code within two hours, free of charge. Hand that code to your new provider and your number transfers automatically, usually within a single working day.

How much roaming data do I actually need in Europe? It depends on how you use your phone abroad. For maps and messaging, 1–3GB is usually enough for a short trip. For streaming and heavy social media use, aim for 5–10GB or more. Frequent travellers often prefer unlimited UK data paired with a 30–35GB roaming allowance abroad — several of the deals Olimit lists, including Lebara and Mozillion SIMs, now build that kind of roaming allowance in from the entry-level plan upward.

What happens to my bill once my phone contract ends? The phone becomes yours outright, but most networks don’t automatically lower your monthly bill — you keep paying the same rate until you actively switch. Moving to a SIM Only plan the moment your contract ends is one of the simplest ways to cut £10–£20 a month, and it’s exactly the kind of switch Olimit is built to make quick.

Do SIM Only prices rise during the contract? Some networks apply an annual price increase, typically each April, tied to inflation or a fixed percentage — always disclosed in the contract terms. Olimit flags this directly on each deal listing where it applies, so you’re not caught off guard partway through a 12- or 24-month contract.

Why Olimit Is Becoming the Default UK SIM Comparison Site

Put it all together and the appeal is straightforward:

Full market coverage — EE, Vodafone, O2, Three, and every major MVNO (Lyca, 1p Mobile, Mozillion, Lebara, Talkmobile, VOXI, Asda Mobile, iD Mobile, SMARTY) in one place
Deal types that match real searches — unlimited, 30-day rolling, 12-month, eSIM, no credit check, international roaming, and tourist eSIM
Transparent roaming data — exact destination counts and data caps shown per deal, not buried in T&Cs
True total cost shown — not just a misleadingly low monthly price
Daily updates — hundreds of live SIM deals and thousands of phone deals, refreshed constantly
No pay-to-rank bias — commission from a sale never changes how a deal is ranked

If your current SIM is quietly overcharging you for European roaming, or you’ve simply been meaning to switch but never found the time to compare things properly, Olimit is worth five minutes before you sign anything. Head to olimit.co.uk and compare the full UK market in one place — SIMs, eSIMs, roaming plans, and phones alike.

Prices, roaming allowances, and network terms change regularly — always check the latest details directly on Olimit before purchasing.