- Mr Plane Guy
- 2 days ago
- 5 min read
The Best International SIM Card for UK Travellers (Do They Actually Exist?)
International SIM cards explained, what actually works abroad & the smartest option for UK travellers
By Mr Plane Guy, Former airline insider, Travel hacker, Plane Honest reviews
Disclosure: This post contains affiliate links. If you click and activate a SIM, I may earn a commission at no extra cost to you. It helps fund the blog (and my airport Pret addiction).
Is There Any International SIM Card?
Short answer: yes, but not in the way most people think.
When people search for:
international SIM card
SIM card for international travel
is there any international SIM card?
What they usually mean is:
“Is there one SIM card I can use abroad without insane roaming charges?”
For UK travellers, the best answer isn’t usually a flashy “global SIM” sold to tourists it’s a UK SIM that’s genuinely travel-friendly.
What Is an International SIM Card?
An international SIM card is any SIM that lets you use your phone across multiple countries without swapping cards or paying daily roaming fees.
In reality, there are two types:
❌ Traditional “Global Travel SIMs”
Marketed as “works in 100+ countries”
Often expensive per MB
Confusing top-ups
Weak UK support
✅ Travel-Friendly UK SIM Cards
Work in the UK and abroad
Include EU roaming
One number, one SIM, year-round
For most UK travellers, option two is better value.
The Best International SIM Card for UK Travellers: Chattr
🇬🇧 Chattr SIM, A UK SIM That Works Internationally
Chattr isn’t marketed as an international SIM card, but for many travellers, that’s exactly what it becomes.
Chattr is a SIM-only UK mobile network built around fairness, flexibility, and simplicity and crucially, it’s travel-friendly by design.
Why Chattr works as an international SIM card
Free EU roaming in 40+ European countries
Use your phone abroad like you do in the UK
No daily roaming fees
One SIM for home and travel
If you mainly travel around Europe, this removes the need to buy a new SIM or eSIM for every trip.
The £1,500 Phone Bill That Stopped Me Guessing About Roaming
This happened to me last April, on my way to Australia, during a short stopover in Beijing.
I meant to sort connectivity properly beforehand. I didn’t.
I assumed I’d be fine using hotel Wi-Fi and a bit of roaming “just for maps”.
A few days later, I received a text from my UK network telling me I’d hit my mobile spending cap. Out of curiosity, I logged in to check.
£1,500!
My phone bill was higher than the flight to China.
Somewhere between maps, background apps and messages, roaming charges quietly stacked up, without me ever realising I was using mobile data.
Beijing wasn’t the problem, guessing was.
I didn’t know exactly when roaming started, what was included, or what counted as chargeable data. That uncertainty is what turned a normal trip into a £1,500 bill.
That’s why, even in Europe, I no longer guess with roaming.
I use one UK SIM that lets me roam like I’m still at home, so my phone behaves the same abroad as it does in the UK, with no daily roaming fees and no surprises.
🔥 Chattr SIM – January Deal
Roam like at home across 40+ European countries, Use code JAN10 for 10% off in January
Rome, Google Maps open, no Wi-Fi hunting, no roaming panic. This is exactly why I use Chattr, roaming in Europe like I’m still at home.
Network, Coverage & Reliability
Chattr runs on O2’s award-winning UK network, which means:
99% UK population coverage
4G and 5G access
Strong, reliable signal both at home and abroad
That matters if you want a SIM card that doesn’t suddenly fall apart the moment you leave the UK.
Chattr Plans (UK + International Use)
Chattr keeps things refreshingly simple:
5GB
25GB
Unlimited data
All plans include:
Unlimited UK calls & texts
Free EU roaming
Unrestricted hotspot (share data freely)
30-day rolling plans (no contract, cancel anytime)
No annual price rises
You can also keep your existing UK number using a PAC code the switch usually completes within one working day.
🔥 Chattr Unlimited SIM, Limited-Time Deal
This is currently Chattr’s strongest offer and makes it one of the best-value SIM for travelling abroad for UK travellers who spend most of their time in Europe.
Unlimited SIM, now just £18/month
(Usually £20)
What you get:
Unlimited 5G data
Unlimited UK calls & texts
Business-grade performance
No contract
No price hikes
Use code: JAN10
Extra Perks (Nice Bonus, Not the Main Event)
Chattr also includes optional member perks, such as:
Discounts at high-street brands (Disney+, Prime, Greggs, Vue, lastminute.com)
Priority tickets & prize draws
Not essential, but a decent extra if you’re switching anyway.
International SIM Card vs Travel eSIM: Which Is Better?
This is where most people get confused.
Choose an international SIM card (like Chattr) if:
You travel frequently
Most trips are within Europe
You want one SIM year-round
You don’t want to reinstall eSIMs every trip
Choose a travel eSIM if:
You travel once or twice a year
You’re going long-haul (USA, Asia, Australia)
You only need data for a short trip
There’s no single “best” option, smart travellers mix both.
International SIM Card FAQs (UK Travellers)
Is there really an international SIM card?
Yes, but for UK travellers, the best option is often a UK SIM with free roaming, not a standalone global SIM sold to tourists.
Which SIM card can be used internationally?
Any SIM with roaming enabled, but plans vary. Travel-friendly UK SIMs like Chattr allow you to use your phone abroad like you do at home.
Is it worth getting an international SIM card?
If you travel regularly, yes. It’s usually cheaper and simpler than buying a new travel SIM or paying roaming fees every trip.
Plane Tip: If you travel often, stop thinking in terms of “travel SIMs”.
A UK SIM that works internationally is usually the smartest, cheapest solution.
Switching this month? Use code JAN10 for 10% off in January and roam around Europe like you’re still at home.
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Hello I’m Paul a travel and flight expert, I spent most of my career working in and around planes with 15 years providing top-notch service with a London-based airline. I became an expert in travel after soaring across the Atlantic up to 10 times a month!
I’m now, producing travel content, reaching millions of viewers monthly. Reporting on travel news, sharing travel tips, reviews, and deals with a sprinkle of humour and a whole lot of authenticity!
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