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Three SIM only deals for March: 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: 15th March 2023.

Three's best SIM only deals

Our favourite SIM only deal this month on Three

Three SIM card
Unlimited data
a month

12-month dealGet this deal

(opens in new window)

We think Three's best value option on SIM only this March is their £19 a month plan below, which comes with unlimited data, plus unlimited minutes and texts on a 12‑month deal:

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 lower-priced networks' deals here:

Their £12 for 120GB plan is a decent deal for March

Three SIM card
120GB data
a month

12-month dealGet this deal

(opens in new window)

If you don't want so much data, Three are also offering this £12 SIM, which includes 120GB data, unlimited minutes and texts on a 12‑month plan. It's another of their best deals:

It's certainly a good deal from Three. No other network can beat them for price on a SIM only plan with 120GB data or more. See under the dropdown to see how the competition it undercuts:

They're also offering 25GB for £8 on SIM only currently

Three SIM card
25GB data
a month

12-month dealGet this deal

(opens in new window)

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:

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 the networks with cheaper plans here:

£7 for 8GB is Three's next best SIM deal in March

Three SIM card
8GB data
a month

12-month dealGet this deal

(opens in new window)

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 8GB data, unlimited minutes and texts for £7 a month:

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 which other networks can beat it:

There's also a nice 3GB for £5 plan with them this month

Three SIM card
3GB data
a month

12-month dealGet this deal

(opens in new window)

Or their £18 for unlimited data SIM plan is worth a look too

Three SIM card
Unlimited data
a month

24-month dealGet this deal

(opens in new window)

To satisfy even bigger data needs, 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:

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 are the networks offering it cheaper:

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's SIM only prices and benefits compare

Ratings stars with the Three logo

We review Three's network in fullRead 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.

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

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Test all the places you'll goCheck 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).

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

Other Three guides