Three's best SIM only deals: 40GB for £8, 80GB for £10
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See how Three compare on price this month vs the competition on SIM only. We've checked each of their plans to find the best. Last updated: 23rd February 2026.
Three's best SIM only deals
The best SIM only deal on Three this month
just
£8
a month
✔ Unlimited mins and 40GB data See full deal
at three.co.uk
(opens in new window)
Out of all the SIM only plans available this February on Three, we'd say their best value deal is their discounted 12‑month SIM below, which gets you 40GB data, plus unlimited minutes and texts for £14 £8 a month:
It’s a discount of £6 a month against the full price, adding up to a £72 saving over the 12 months.
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 are other networks you can beat it on:
Or their £10 for 80GB SIM plan is worth a look too
just
£10
a month
✔ Unlimited mins and 80GB data See full deal
at three.co.uk
(opens in new window)
For more monthly data, you might like the discounted £10 SIM only deal running on Three at the moment. It's a 12‑month plan, which comes with 80GB data, unlimited minutes and texts too:
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 the networks with cheaper plans here:
Three are also offering 120GB for £12 on SIM only
just
£12
a month
✔ Unlimited mins and 120GB data See full deal
at three.co.uk
(opens in new window)
To get even more data, we'd say this is one of Three's best deals on SIM only this month too. It's a discounted 12‑month plan, comes with 120GB data, unlimited minutes and texts for £18 £12 a month:
That’s £72 you’ll save over 12 months with the deal thanks to the £6 monthly discount.
Compared to Three's other deals, this comes out among the best. But it's worth knowing you can get a lower price elsewhere, even on other providers that use the Three network. Here's which other networks can beat it:
They've also got a unlimited data for £18 SIM plan at the moment
just
£18
a month
✔ Unlimited mins and unlimited data See full deal
at three.co.uk
(opens in new window)
For people who need even more data, have a look at Three's discounted unlimited data SIM below at £28 £18 a month, as it's another good deal. It's on a 12‑month plan and comes with unlimited data, unlimited minutes and texts:
That means a total saving of £120 when you add up the £10 discount over 12 months.
It might be one of Three's best deals on SIM only but you can get a lower price for a similar plan on other providers, even ones that use the Three network. See where you can get 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