You're probably tired of being locked into a twenty-four-month contract that feels more like a mortgage than a phone plan. It happens to the best of us. We sign up for the shiny new flagship, and a year later, we're stuck paying £60 a month for data we don't even use. That’s why 3 network pay as you go has been making a massive comeback lately. Honestly, the math just works out better for a lot of people.
It's not just for burner phones or your nan’s old Nokia anymore.
Things have changed.
Three (the UK network, obviously) has pivoted their entire PAYG model to behave more like a flexible subscription. You aren't stuck licking stamps or finding a corner shop to "top up" every five minutes. You just buy a "Data Pack" and go about your life. If you want to stop next month? You just stop. No exit fees. No scary letters from debt collectors. No credit checks.
The weird truth about Three’s coverage and 5G
If you’ve lived in a rural area, you might have heard people complain about Three. Ten years ago, they were right. It was spotty. But since the 5G rollout started, the 3 network pay as you go experience has genuinely flipped the script.
Three actually holds more 5G spectrum than any other UK operator. We’re talking about a massive 100MHz block of contiguous spectrum. In plain English? It means their 5G is often way faster than EE or O2 in city centers because the "pipe" is wider. If you're using a PAYG SIM in a 5G-ready phone, you're getting those speeds without the "premium" tax that some contract providers try to sneak in.
But look, let's be real. Indoors, Three can still be a bit finicky because of the frequencies they use. They rely heavily on the 3.4GHz and 3.6GHz bands for 5G. These are lightning-fast but don't like thick brick walls. If you live in a basement flat in a Victorian terrace, check the coverage map before you commit. Or, better yet, just buy a £10 SIM and test it. That’s the whole point of not being in a contract.
What actually happens when you top up?
Most people get confused here. You have "Credit" and you have "Data Packs."
Credit is just cash sitting on your account. It lasts until you spend it on a call or a text. It’s expensive if you use it for data—we’re talking 1p per MB. That adds up fast.
Data Packs are the secret sauce. You trade your credit for a bundle. For example, their "Value" packs usually start around £10 for a decent chunk of data, but the big wins are the Unlimited packs. If you’re a heavy streamer, you can get Unlimited data on 3 network pay as you go for about £35. Sometimes they run promos where it’s even cheaper. It’s basically a rolling monthly contract but without the "contract" part.
The "Go Roam" situation is kinda annoying now
We have to talk about roaming. It used to be Three’s biggest selling point. You could go to New York or Sydney and use your data like you were in London.
Then Brexit happened.
Now, if you’re on a new 3 network pay as you go account, roaming isn't "free" in the way it used to be. You have to buy a "Roam Further" add-on or pay a daily fee (£2 in Europe, £5 elsewhere). It’s still cheaper than a lot of the big networks, but it’s not the "global local" vibe they used to have. If you’re a legacy customer who has held onto an old SIM for five years, don't throw it away! You might still have those old-school roaming perks grandfathered in.
Why the "Data Rewards" SIM is a different beast
There is this specific thing called the 3 Data Rewards SIM. It's legendary in tech circles. Essentially, you get 200MB of data every single month for free.
Yes, for life.
It’s not enough to watch Netflix, obviously. But for a secondary phone, a GPS tracker in your car, or an emergency backup SIM in your wallet? It’s unbeatable. You just register the SIM, and every month, 200MB hits the account. No top-up required. It’s the kind of loophole that feels like it shouldn’t exist in 2026, but Three has kept it alive for years.
Comparing the "Big Four" PAYG options
People always ask: "Why not just go with Giffgaff or Tesco Mobile?"
Good question.
Giffgaff runs on O2. Tesco runs on O2. Smarty—which is actually owned by Three—runs on Three.
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Here is where it gets spicy. If you want the absolute cheapest price, you usually go to Smarty. But if you want access to the Three+ rewards app, you have to be on the actual 3 network pay as you go plan.
The Three+ app is actually decent. It’s not just "win a free coffee" fluff. They do £1 Cineworld tickets and discounted Uber Eats pretty regularly. If you use those twice a month, the "premium" you pay for being on the main Three network instead of a sub-brand like Smarty basically pays for itself. You’re trading a couple of quid for actual, tangible stuff you’d buy anyway.
Setting up your device (The stuff no one tells you)
When you get your SIM, your phone might not automatically grab the APN settings. This is the #1 reason people think their SIM is broken.
If you have no data, go to your Settings. Look for Mobile Data Networks.
The APN should be: three.co.uk
The username and password should be left blank.
If you’re on an iPhone, it usually "just works" after a carrier update. If you’re on a niche Android brand like Xiaomi or Nothing, you might have to punch those letters in manually. Also, make sure "Data Roaming" is turned ON in your phone settings if you’re using one of their travel packs, or it simply won't trigger.
The death of the "3-2-1" plan
We should probably pour one out for the 3-2-1 plan. It was the gold standard: 3p a minute, 2p a text, 1p a MB.
Three killed it off for new customers a while back. If you find an old 3-2-1 SIM on eBay, be careful. They are highly sought after, but Three has been migrating people away from them. If you're looking for that specific rate today, you won't find it on the official site. The new standard rates are higher, which is why everyone is pushing those Data Packs I mentioned earlier.
Is it actually "Unlimited"?
Mostly.
On a 3 network pay as you go unlimited pack, there’s a "fair use" policy, but for domestic UK use, it's basically impossible to hit it unless you're trying to run a literal server farm out of your bedroom. They do have a 12GB limit for roaming in "Go Roam" destinations, though. Don't think you can go to Spain and tether your entire family's iPads to your phone to watch 4K movies. You'll get throttled or cut off pretty quickly.
How to move your number (The PAC code dance)
You don't have to lose your number. This is a common myth that keeps people trapped in expensive contracts.
- Text 'PAC' to 65075 from your old network.
- They send you a 9-digit code.
- Give that code to Three when you activate your PAYG SIM.
- Within 24 hours, your old number jumps over to the new SIM.
It's literally that easy. The old account closes automatically, and you’re free.
Actionable Steps for Switching
If you're ready to jump ship and try 3 network pay as you go, don't just walk into a shop and buy the first thing you see.
First, grab a free SIM from the Three website. They usually ship them for free. Don't put any money on it yet. Put it in your phone and check the signal bars in your house, your office, and your favorite pub.
Second, download the Three+ app immediately. Check the rewards. If you see stuff you actually use, the PAYG route is a no-brainer.
Third, if the signal is great, top up via the Three UK app—never via the website if you can help it, as the app is much more stable for card payments. Select a Data Pack that matches your usage. If you use 10GB a month, don't buy the Unlimited pack. Save the £15.
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Finally, set up an "Auto-renew" if you want the convenience of a contract without the credit check. It’ll grab the money from your card every 30 days and keep your data flowing. If you have a lean month and need to save cash, just toggle it off. You're in control. That’s the real beauty of it.