Best Three SIM offers: 40GB for £8, 160GB for £12
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Find out which choices on Three's SIM only came top of our comparisons against every other UK network this month. Last updated: 14th November 2025.
Three's best SIM only deals
Our favourite SIM only deal of the month on Three
just
£12
a month
Increased to: £16.60 on April 1 2027
✔ Unlimited mins and 160GB data See full deal
at three.co.uk
(opens in new window)
Looking at what you can get on SIM only with Three this November, our best-rated deal would be their discounted 24‑month plan below, which comes with 160GB data, plus unlimited minutes and texts for £12 a month:
Even though it's in our pick of Three's best SIM only deals, you can actually beat it on price with other providers, including ones that also use the Three network. See the networks that beat it here:
Three are also offering 40GB for £8 on SIM only
just
£8
a month
✔ Unlimited mins and 40GB data See full deal
at three.co.uk
(opens in new window)
For a smaller amount of data, we also think this discounted £8 Three SIM is one of their best options. It comes with 40GB data, unlimited minutes and texts on a 12‑month deal:
While this is a good enough deal to make it into the best of Three's SIMs, you can beat it for price (even if you definitely want a provider that uses the Three network). Here are the networks where it'd cost less:
They've also got a 25GB for £7 SIM plan at the moment
just
£7
a month
✔ Unlimited mins and 25GB data See full deal
at three.co.uk
(opens in new window)
If you don't want so much data, Three's discounted £16 £7 SIM below is another of their best deals this month. For £7 a month, it offers 25GB data, unlimited minutes and texts on a 12‑month plan:
That means a total saving of £108 when you add up the £9 discount over 12 months.
It's a good enough deal to get into Three's best SIMs but you can actually get a lower price for a similar plan elsewhere, even if you definitely want it to use the Three network. See which networks that are cheaper here:
Three's £9 for 60GB is our next best choice now
just
£9
a month
✔ Unlimited mins and 60GB data See full deal
at three.co.uk
(opens in new window)
If you want even more data, the next best SIM only plan on Three in our opinion is their discounted 12‑month one below. For £16 £9 a month, you get 60GB data, plus unlimited minutes and texts:
In total, that discount of £7 a month means you’re looking at a saving of £84 over the 12‑month deal.
In comparison to the rest of Three's current SIM only plans, it's one of the best. But it is beatable on price, even if you're set on joining a provider that uses the Three network. Here's where else you can get a lower price:
Their £18 SIM with unlimited data is our next favourite this November
just
£18
a month
✔ Unlimited mins and unlimited data See full deal
at three.co.uk
(opens in new window)
For even more data, another good deal on Three at the moment is their discounted £28 £18 SIM only plan here, which includes unlimited data instead, plus unlimited minutes and texts:
Getting £10 off a month means you’ll save £120 over the course of your 12‑month deal.
It does enough to get into our pick of Three's best SIMs but that doesn't mean it's unbeatable on price. Other providers (even ones that use the Three network) can beat it. See who's offering it for less here:
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How Three compare on SIM only prices and benefits
We said in our full review of the Three network that our favourite thing about them is their fast 4G and 5G speeds as well as their encouraging 5G coverage.
On SIM only you can take a 1-month, 12-month or 24-month contract. Typically the longer the contract, the lower your monthly cost. But it’s always worth shopping around to find their best current deal.
Three’s “Lite” plans are much cheaper than the sorts of deals you’d get on other main networks. Three also have some premium plans with extra benefits baked in. You can take these on 12 or 24-month contracts.
All Three plans give you access to their handy Three+ rewards app. And you get EU and worldwide roaming passes included on their premium Value and Complete plans, as well as these other benefits.
Useful link: Read our full Three review
Other good things to know about Three’s SIM only plans
Three will send your SIM card within 3-5 working days. You’ll receive a package with every size of SIM in it, so you can fit your SIM into every phone. Three also offer eSIMs (see more info here).
You can return your SIM within 14 days to get a full refund if you’re not satisfied. Returning things you bought in a Three store is a bit more tricky, so read the full terms and conditions here to learn more.
To join on any Three SIM only contract you’ll have to pass a credit check. If you were rejected for a contract on Three then you can either take a monthly PAYG bundle or top up with credit and pay as you go.
If you want to keep your number when switching to Three from another network, you can do so by requesting a PAC from your old provider and giving it to Three at any time. Here’s their guide on how to do this.
Useful link: Compare all Three SIMs