Three SIM only deals for June: how they compare on price

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We've taken each of Three's best SIM only plans this month and compared them on price with other UK networks. Here's what we found. SIM Sherpa is your trusty guide. Last updated: 1st June 2023.
Three's best SIM only deals
The best overall Three SIM only deal this month
We think Three's best value option on SIM only this June is their £12 a month plan below, which comes with 120GB data, plus unlimited minutes and texts on a 12‑month deal:
If you're open to joining other networks than Three, you can actually get a similar deal for less, even with providers whose SIMs also use the Three network. See the networks that beat it here:
We also like their £8 for 25GB plan
For people who don't need that much data, you might like the £8 SIM only deal running on Three at the moment. It's a 12‑month plan, which comes with 25GB data, unlimited minutes and texts too:
While it's good enough to be in our pick of Three's best SIM only deals, other providers do still have similar plans for less, even ones that also use the Three network. Here are the networks where it'd cost less:
Their 3GB for £5 SIM is another good option
If that'd be too much data for you, we'd say this is one of Three's best deals on SIM only this month too. It's a 12‑month plan, comes with 3GB data, unlimited minutes and texts for £5 a month:
It's definitely one of Three's best. But it's not market-leading. You can get a similar plan on other providers for less, even if you need your SIM to use the Three network. See which networks that are cheaper here:
Three's unlimited data for £19 plan is a good option too
If you're even more data-hungry, have a look at Three's unlimited data SIM below at £19 a month, as it's another good deal. It's on a 12‑month plan and comes with unlimited data, unlimited minutes and texts:
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. Here's where else you can get a lower price:
Their £18 for unlimited data plan is a decent deal for June
If that's more data than you need, another option for you on Three, is their 24‑month SIM below, which costs £18 a month for unlimited data and comes with unlimited minutes and texts:
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). See who's offering it for less here:
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How Three's deals compare with other networks

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More about Three's SIM only plans
How Three's SIM only prices and benefits compare
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.
In terms of price, they’re the cheapest of the main networks (EE, Vodafone, O2, Three) and are fairly cheap compared to all providers. Their best deals tend to be their hidden deals on 12-month contracts.
Nowadays, Three are fairly low frills for a main network. They don’t offer much extra outside of their new Three+ rewards app and there are a few discounts on additional plans added to your account.
Useful link: Read our full Three review
Useful information about Three’s SIM only deals
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).
Once your SIM arrives you’ll have 14 days to return it and get a full refund if you’re unhappy with it. There are some finickity rules about returning things bought in-store, so have a read of their terms and conditions for more information.
You’ll have to pass a credit check to get on a pay monthly SIM only plan with Three. If you’ve failed a credit check with Three you can take a monthly bundle or top up your SIM 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