Written by Becky Lima-Matthews
Visiting the UK for more than 30 days for work or study? We’ve rounded up the best UK SIM cards for your medium-term stay. An extended trip to the UK means you’ll want to get the most for your money—not rinsing cash on international rates.
Pro tip: Living here but don’t want a contract? See our post on Prepaid UK SIM cards.
First: Knowing your SIMs
Googling SIM types generally leads you to SIM sizes. The three options are nano, micro or standard—most modern phones use Nano. Fortunately, almost all UK providers use “trio SIMs”, which fit all three fittings. So the days of using converter kits or nervously cutting around the chip are more or less over.
Now, on to the two main SIM plans. These are either data + voice or data-only. As the name suggests, the former lets you make and receive calls, while the latter doesn’t.
Contract-free SIM-only deals in the UK
In the UK, you can only sign up for a long-term contract if you’re a resident—and you’ll usually be subject to a credit check first. So what if you’re staying for a few months or a year, but not making a permanent move? While the UK “big four” (EE, Vodafone, Three, 02) have short-term options, they’re often restricted to 30 days and some require a credit check anyway.
Luckily, there are a number of other providers offering contract-free, month-to-month SIM-only deals, which don’t require credit checks or stacks of paperwork. These provide the benefits and flexibility of prepaid/PAYG plans, with the perks of contracts. Some of the names in this game include giffgaff, VOXI, SMARTY and Lebara. Here’s how they currently stack up.
Note: All UK SIM cards listed here are data + voice. Calls are, unless otherwise specified, limited to within the UK. This is not an exhaustive list of packages, just an overview.
Quick comparison: contract-free UK SIM plans
| Provider | Data | Price/month | Calls & Texts | Network | Best for |
|---|---|---|---|---|---|
| SMARTY | 100GB | £10.00 | Unlimited | Three | Best value; refund for unused data |
| SMARTY | 100GB | £12.00 | Unlimited | Three | Best value; refund for unused data |
| SMARTY | Unlimited | £17.00 | Unlimited | Three | Best value unlimited |
| VOXI | 25GB | £12.00 | Unlimited | Vodafone | Unlimited social + music |
| VOXI | Unlimited | £35.00 | Unlimited | Vodafone | Unlimited everything inc. video |
| giffgaff | 15GB | £10.00 | Unlimited | O2 | Flexible — pause or cancel anytime |
| giffgaff | 30GB | £15.00 | Unlimited | O2 | Flexible — pause or cancel anytime |
| Lebara | 30GB | £10.00 | Unlimited UK + 100 intl mins | Vodafone | Best for international calls |
| Lebara | Unlimited | £25.00 | Unlimited UK + unlimited intl mins | Vodafone | Best for international calls |
| Data | Price | Talk(min) / Texts | 5G ready | Link |
|---|---|---|---|---|
| 25GB | £12.00 (with unlimited social media + music) | Unlimited / Unlimited | Yes | |
| 30GB | £15.00(with unlimited video + social media) | Unlimited / Unlimited | Yes | |
| 100GB | £20.00 (with unlimited video + social media) | Unlimited / Unlimited | Yes | |
| Unlimited | £35.00(with unlimited everything) | Unlimited / Unlimited | Yes |
| Call minutes / Text | Data | Monthly cost | Link |
|---|---|---|---|
| Unlimited / Unlimited | 100GB | £10.00 | |
| Unlimited / Unlimited | 100GB | £12.00 | |
| Unlimited / Unlimited | Unlimited | £17.00 | |
| Call minutes / Text | Data | Monthly cost | Link |
|---|---|---|---|
| Unlimited UK + 100 international mins / Unlimited | 30GB | £10.00 | |
| Unlimited UK + unlimited international mins / Unlimited | 100GB | £20.00 | |
| Unlimited UK + unlimited international mins / Unlimited | Unlimited | £25.00 | |
| Call minutes / Text | Data | Monthly cost | Link |
|---|---|---|---|
| Unlimited / Unlimited | 5GB | £8.00 | |
| Unlimited / Unlimited | 15GB | £10.00 | |
| Unlimited / Unlimited | 30GB | £15.00 | |
| Unlimited / Unlimited | 80GB | £20.00 | |
Notes on the providers
VOXI: VOXI offers unlimited data for social apps—which goes for Facebook, WhatsApp, Instagram and a few others. They’re also the first non-contract provider to offer an unlimited 5G ready service.
SMARTY: Uses the Three network. On some plans, you can get money back if you’re not using all your data, which is great if you don’t know how much you’ll be using.
giffgaff: You can switch, upgrade or take a break from your tariff at any time. There are also cash or credit “payback points” for recommending new members or answering questions in the community forums.
Lebara: Runs on the Vodafone network. Popular with international residents thanks to generous international call minutes included in all plans. Now also offers eSIMs (from October 2025).
Unlocking mobile phones in the UK
From December 2021, mobile carriers in the UK were banned from selling locked cell phones. While they’d had to unlock phones on request for many years, they’d still been allowed to sell them locked. Having access to an unlocked phone from the get-go can be a money-saver, as it makes it easier to switch providers.
PAYG UK SIM cards
Option number two is buying a plain-old PAYG (Pay-As-You-Go) SIM. These have changed a lot over the years and often come with minimum top-up fees and add-ons. To be cost-effective, it’s better to opt for a bundle—but most bundles are for 30 days. You’ll see some of the names above popping up in the PAYG market too—the lines between PAYG and contract-free but contract-like are increasingly blurred. Read more about PAYG UK SIM cards.
Saving data
Whatever option you go for, you’ll want to make your data allowance go as far as possible. A few tips will keep your mobile data usage in check:
1. Turn off apps you don’t need—background applications (especially social media, e-mail, calendar, GPS etc). Turn off your notifications too—do you really need to know where your far-off friends checked-in for a coffee?
2. Only use GPS when you need it, and make sure your GPS data only roams when you do!
3. Install a data-managing app like My Data Manager for Android or Data man for iPhone to keep tabs on your usage.
4. Compress your data with free apps on Google Play or the AppStore.
While we do our best to make sure it is correct, all information is subject to change. Post published in September, 2018. Last updated March 13, 2026.
