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Three SIM only deals for September: 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: 28th September 2023.

Three's best SIM only deals

Our highest-rated SIM only deal on Three this month

Three SIM card
Unlimited data
a month

24-month dealGet this deal

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We'd say the best SIM only plan Three are selling this September is their 24‑month unlimited data deal below, which comes in at £18 a month and includes unlimited minutes and texts too:

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 £12 for 120GB is our next best choice now

Three SIM card
120GB data
a month

12-month dealGet this deal

(opens in new window)

For people who don't need that much data, the next best SIM only plan on Three in our opinion is their 12‑month one below. For £12 a month, you get 120GB data, plus unlimited minutes and texts:

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 £10 SIM with 60GB is our next favourite this September

Three SIM card
60GB data
a month

24-month dealGet this deal

(opens in new window)

If that'd be too much data for you, another good deal on Three at the moment is their £10 SIM only plan here, which includes 60GB data instead, plus unlimited minutes and texts:

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:

We also like their £8 for 25GB plan

Three SIM card
25GB data
a month

12-month dealGet this deal

(opens in new window)

For those with smaller data needs, our next best pick of Three SIM only plans is their 12‑month £8 deal below, which gets you 25GB data and unlimited minutes and texts:

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 where you can beat it on other networks:

Compare all SIM only plans

Compare deals from all networks

How Three's deals compare with other networks

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More about Three's SIM only plans

How Three compare on SIM only prices and benefits

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We go over their network and benefitsRead our full review

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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 network map screenshot

Check signal where you use your phoneCheck your signal

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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

Other Three guides