By Three has a number of hidden SIM-only deals, including 12GB for £6, 40GB for £8, 60GB data for £10, and 120GB data for £12. Save money with their exclusive SIMO deals.
In the UK, Three offers a number of hidden SIM-only deals that you won’t be able to find if you go directly to their website. You can save a substantial amount of money with these hidden deals. For instance, you can get 40GB data for £8 or 60GB data for £10. There’s also 120GB data for £12, and 250GB data for £16.
Alongside their ‘Lite SIMO’ plans, Three also offers ‘Value SIMO’ and ‘Complete SIMO’ plans. If you upgrade to one of these Value or Complete SIMO plans, you’ll get inclusive roaming, along with a subscription to Paramount+ service.
In this article, we’ll look at Three’s best SIM-only deals, including all of the hidden plans that can save you money. We’ll also compare the Lite, Value and Complete SIM-only plans from Three, including the benefits of each one. We’ll also look at how you can transfer your existing phone number to Three.
| Prices From: | £5 per month |
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| Contract Length: | 12 month or 24 month contract |
| Hidden SIM Only Deals: | |
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Contents
Best Three SIM Only Deals
In the UK, Three offers a number of hidden SIM-only deals. You’ll need to follow special links to their website to find these hidden deals, which can save you up to £7 per month against the normal price.
- If you’re a light mobile user, Three offers 3GB data for £5 and 12GB data for £6. On these plan, you’ll get more data and for a lower monthly price than if you were to go directly to Three’s website.
- For most users, our recommended plans is 40GB data for £8. This is heavily discounted from the normal price of £14 per month. There’s also 60GB data for £10, if you’re looking for a bit more data.
- For heavy data users, there’s 120GB data for £12, 250GB data for £16, and unlimited data for £20. This is reduced from the standard price on Three’s website, which is 120GB data for £16 and unlimited data for £28.
The following table shows the best 12-month SIM-only deals from Three:
| Plan | Data | Monthly Cost | |
|---|---|---|---|
Lite
| 3GB data | £5.00 per month 12 month contract Monthly cost rising to £6.00 on 1 Apr 2026 | See deal |
Lite
| 12GB data | £6.00 per month 12 month contract Monthly cost rising to £7.25 on 1 Apr 2026 | See deal |
Lite
| 40GB data | £8.00 per month 12 month contract Monthly cost rising to £9.25 on 1 Apr 2026 | See deal |
Lite
| 60GB data | £10.00 per month 12 month contract Monthly cost rising to £11.25 on 1 Apr 2026 | See deal |
Lite
| 80GB data | £11.00 per month 12 month contract Monthly cost rising to £12.25 on 1 Apr 2026 | See deal |
Lite
| 120GB data | £12.00 per month 12 month contract Monthly cost rising to £13.50 on 1 Apr 2026 | See deal |
Lite
| 250GB data | £16.00 per month 12 month contract Monthly cost rising to £17.50 on 1 Apr 2026 | See deal |
Lite
| Unlimited data | £23.00 per month 12 month contract Monthly cost rising to £24.50 on 1 Apr 2026 | See deal |
If you’re looking for unlimited data, you can save more when you sign up on a longer 24-month contract:
| Plan | Data | Monthly Cost (rising to £21.50 on 1 Apr 2026 £23.00 on 1 Apr 2027) |
|
|---|---|---|---|
Lite
| Unlimited data | £20.00 per month 24 month contract | See deal |
All of these deals are Lite SIMO plans (previously known as ‘Standard SIMO’ plans). They’ll give you access to Three’s 5G network with no speed limits or restrictions. You’ll also get access to the Three+ app included as standard.
For additional benefits like inclusive roaming and Paramount+, you can choose a ‘Value SIMO’ or ‘Complete SIMO’ plan instead (see below).
Lite, Value & Complete SIMO Plans
If you’re looking for additional plan benefits, you can upgrade your ‘Lite SIMO’ plan to a ‘Value SIMO’ plan or a ‘Complete SIMO’ plan from Three.
The following table shows a side-by-side comparison of the three types of plan:
| Lite SIMO | Value SIMO | Complete SIMO | |
|---|---|---|---|
 |
 |
 |
|
| Data Plans | |||
| 3GB Data | £5 per month | £10 per month | £15 per month |
| 8GB Data | £7 per month | £12 per month | £17 per month |
| 25GB Data | £8 per month | £10 per month | £13 per month |
| 60GB Data | £10 per month | £15 per month | £20 per month |
| 120GB Data | £12 per month | £17 per month | £22 per month |
| 250GB Data | £16 per month | £25 per month | £30 per month |
| Unlimited Data | £20 per month | £23 per month | £26 per month |
| Inclusive Allowances | |||
| Minutes & Texts |
Unlimited | Unlimited | Unlimited |
| Personal Hotspot | ✔ | ✔ | ✔ |
| Speed | 5G with no speed limits | 5G with no speed limits | 5G with no speed limits |
| Additional Plan Features | |||
| Three+ Offers |
✔ Yes | ✔ Yes | ✔ Yes |
| Paramount+ | ✘ No | ✔ First half of plan | ✔ Entire plan |
| Inclusive Roaming | ✘ Chargeable | ✔ 14 days per year | ✔ 28 days per year |
You’ll normally pay about £5 per month more to upgrade to a ‘Value SIMO’ plan. This gives you inclusive Paramount+ for the first half of your contract (e.g. you’ll get 6 months of inclusive Paramount+ Standard on a 12 month plan). You’ll also get 14 daily Go Roam passes each year, saving you up to £7 per day when you travel abroad.
For a ‘Complete SIMO’ plan, you’ll normally pay about £10 per month more. This gives you inclusive Paramount+ Standard for the entire length of your contract (worth £7.99 per month), plus 28 daily Go Roam passes each year (worth up to £7 per day).
SIM Only Deals: By Data Allowance
3GB Data
If you’re a light mobile user, Three’s entry-level Lite SIMO plan is available from just £5 per month when you order through one of the links below:
| Plan | Data | Monthly Cost | |
|---|---|---|---|
Lite
| 3GB data | £5.00 per month 12 month contract Monthly cost rising to £6.00 on 1 Apr 2026 | See deal |
Lite
| 3GB data | £5.00 per month 24 month contract Monthly cost rising to £6.00 on 1 Apr 2026 £7.00 on 1 Apr 2027 | See deal |
Value
| 3GB data | £10.00 per month 24 month contract Monthly cost rising to £11.00 on 1 Apr 2026 £12.00 on 1 Apr 2027 | See deal |
Value
| 3GB data | £10.00 per month 12 month contract Monthly cost rising to £11.00 on 1 Apr 2026 | See deal |
Complete
| 3GB data | £15.00 per month 24 month contract Monthly cost rising to £16.00 on 1 Apr 2026 £17.00 on 1 Apr 2027 | See deal |
Complete
| 3GB data | £15.00 per month 12 month contract Monthly cost rising to £16.00 on 1 Apr 2026 | See deal |
A 3GB data plan can be sufficient if you mainly use a wi-fi connection at home and at work. With your 3GB data allowance, you’ll be able to browse the web for around one hour per day. Alternatively, you can watch about 4 hours of online video each month in standard-definition (SD) quality on this plan.
8GB Data
Three’s 8GB data plan is a good choice if you’re looking for a little more data, but if you still use less data than the average UK mobile user.
At the moment, Three offers a hidden 8GB SIM-only deal that costs just £6 per month. This also includes unlimited UK minutes and unlimited UK texts.
| Plan | Data | Monthly Cost | |
|---|---|---|---|
Lite
| 8GB data | £7.00 per month 24 month contract Monthly cost rising to £8.25 on 1 Apr 2026 £9.50 on 1 Apr 2027 | See deal |
Lite
| 8GB data | £7.00 per month 12 month contract Monthly cost rising to £8.25 on 1 Apr 2026 | See deal |
Value
| 8GB data | £12.00 per month 12 month contract Monthly cost rising to £13.25 on 1 Apr 2026 | See deal |
Value
| 8GB data | £12.00 per month 24 month contract Monthly cost rising to £13.25 on 1 Apr 2026 £14.50 on 1 Apr 2027 | See deal |
Complete
| 8GB data | £17.00 per month 12 month contract Monthly cost rising to £18.25 on 1 Apr 2026 | See deal |
Complete
| 8GB data | £17.00 per month 24 month contract Monthly cost rising to £18.25 on 1 Apr 2026 £19.50 on 1 Apr 2027 | See deal |
An 8GB data plan should allow you to browse the web for around 2.5 hours per day or to watch about 20 minutes of standard-definition video each day. However, things like HD-quality video streaming can use up your data very quickly (e.g. just 3 hours of HD video will use up 8GB of data) so are best avoided on this plan.
40GB Data
For the average mobile user, we’d recommend Three’s 40GB per month data plan. Starting from just £8 per month, this gives you lots of data at an affordable price.
The following table shows Three’s latest 40GB per month deals:
| Plan | Data | Monthly Cost | |
|---|---|---|---|
Lite
| 40GB data | £8.00 per month 12 month contract Monthly cost rising to £9.25 on 1 Apr 2026 | See deal |
Lite
| 30GB data | £8.00 per month 24 month contract Monthly cost rising to £9.25 on 1 Apr 2026 £10.50 on 1 Apr 2027 | See deal |
Value
| 30GB data | £10.00 per month 12 month contract Monthly cost rising to £11.25 on 1 Apr 2026 | See deal |
Complete
| 30GB data | £13.00 per month 24 month contract Monthly cost rising to £14.25 on 1 Apr 2026 £15.50 on 1 Apr 2027 | See deal |
Value
| 30GB data | £18.00 per month 24 month contract Monthly cost rising to £19.25 on 1 Apr 2026 £20.50 on 1 Apr 2027 | See deal |
A 40GB data plan will allow you to browse the web for about 400 hours per month (up to 13 hours per day). Alternatively, you can stream about 7,000 songs or you can watch 50 hours of standard-definition video online.
60GB Data
If you’re looking for a bit more data, you can upgrade to Three’s 60GB per month data plan. This is currently available for £10 per month.
The following table shows Three’s latest 60GB per month deals:
| Plan | Data | Monthly Cost | |
|---|---|---|---|
Lite
| 60GB data | £10.00 per month 24 month contract Monthly cost rising to £11.25 on 1 Apr 2026 £12.50 on 1 Apr 2027 | See deal |
Lite
| 60GB data | £10.00 per month 12 month contract Monthly cost rising to £11.25 on 1 Apr 2026 | See deal |
Value
| 60GB data | £15.00 per month 12 month contract Monthly cost rising to £16.25 on 1 Apr 2026 | See deal |
Value
| 60GB data | £15.00 per month 24 month contract Monthly cost rising to £16.25 on 1 Apr 2026 £17.50 on 1 Apr 2027 | See deal |
Complete
| 60GB data | £20.00 per month 24 month contract Monthly cost rising to £21.25 on 1 Apr 2026 £22.50 on 1 Apr 2027 | See deal |
Complete
| 60GB data | £20.00 per month 12 month contract Monthly cost rising to £21.25 on 1 Apr 2026 | See deal |
A 60GB data plan will allow you to browse the web for about 600 hours per month (up to 20 hours per day). Alternatively, you can watch 75 hours of standard-definition video or 20 hours of high-definition video online.
120GB Data
If you’re a heavy mobile user, Three offers 120GB data for £12. This is more than enough data for the majority of mobile users, and is a cheaper alternative to the 250GB and unlimited data plans.
| Plan | Data | Monthly Cost | |
|---|---|---|---|
Lite
| 120GB data | £12.00 per month 24 month contract Monthly cost rising to £13.50 on 1 Apr 2026 £15.00 on 1 Apr 2027 | See deal |
Lite
| 120GB data | £12.00 per month 12 month contract Monthly cost rising to £13.50 on 1 Apr 2026 | See deal |
Value
| 120GB data | £17.00 per month 12 month contract Monthly cost rising to £18.50 on 1 Apr 2026 | See deal |
Value
| 120GB data | £17.00 per month 24 month contract Monthly cost rising to £18.50 on 1 Apr 2026 £20.00 on 1 Apr 2027 | See deal |
Complete
| 120GB data | £22.00 per month 24 month contract Monthly cost rising to £23.50 on 1 Apr 2026 £25.00 on 1 Apr 2027 | See deal |
Complete
| 120GB data | £22.00 per month 12 month contract Monthly cost rising to £23.50 on 1 Apr 2026 | See deal |
250GB Data
If you’re looking for a plan with lots of data, Three is currently offering 250GB data for £16/month. This is a cheaper alternative to their unlimited data SIM card which starts from £20/month.
| Plan | Data | Monthly Cost | |
|---|---|---|---|
Lite
| 250GB data | £16.00 per month 12 month contract Monthly cost rising to £17.50 on 1 Apr 2026 | See deal |
Lite
| 250GB data | £16.00 per month 24 month contract Monthly cost rising to £17.50 on 1 Apr 2026 £19.00 on 1 Apr 2027 | See deal |
Unlimited Data
At present, Three offers an unlimited data SIM card for just £20/month. This is a hidden deal which is only available when you purchase through this link.
The following table shows Three’s best unlimited data deals:
| Plan | Data | Monthly Cost | |
|---|---|---|---|
Lite
| Unlimited data | £22.00 per month 24 month contract Monthly cost rising to £23.50 on 1 Apr 2026 £25.00 on 1 Apr 2027 | See deal |
Lite
| Unlimited data | £23.00 per month 12 month contract Monthly cost rising to £24.50 on 1 Apr 2026 | See deal |
Value
| Unlimited data | £27.00 per month 24 month contract Monthly cost rising to £28.50 on 1 Apr 2026 £30.00 on 1 Apr 2027 | See deal |
Value
| Unlimited data | £28.00 per month 12 month contract Monthly cost rising to £29.50 on 1 Apr 2026 | See deal |
Complete
| Unlimited data | £32.00 per month 24 month contract Monthly cost rising to £33.50 on 1 Apr 2026 £35.00 on 1 Apr 2027 | See deal |
Complete
| Unlimited data | £33.00 per month 12 month contract Monthly cost rising to £34.50 on 1 Apr 2026 | See deal |
All of Three’s unlimited data plans include 5G at no extra cost, with no hidden fair use limits or restrictions on how much you can download. You’ll also get the fastest available download speeds on Three’s network.
Tethering and personal hotspot are also included on all plans, allowing you to share your unlimited data allowance with other devices.
Keeping Your Phone Number
If you’re switching to Three, it’s a straightforward process keeping your current phone number.
Start by asking your current mobile network to give you a PAC Code. You can get one by texting PAC to 65075, or you can request one online through your mobile network’s website or app.
Once you’ve gotten your PAC Code, you’ll be able to place your order online with Three. You can provide them with the PAC Code when you sign up, or wait until the SIM card arrives and then fill out this form on their website.
For step-by-step instructions on transferring your phone number to Three, please select your current mobile network from the drop-down menu below:
For more information, see our full guide to transferring your phone number between networks.
More Information
To get one of Three’s hidden SIM-only deals, tap on the relevant plan in the comparison tables above. You’ll then be taken to the Three website where you can place your order online.
Nazar Hussain said:
Today (28/01/2023) Three is advertising unlimited for £12 per month, yesterday I renewed my 24m contract for £16 per month. I asked for PAC code first and after half hour of arguing and rejecting all other deals offered, I was given the £16 deal which I have been on for about 4 years now.
Dave L said:
The table near the top, above the contents is missing the 4GB data for £6 and 100GB for £15. Perhaps these were omitted intentionally.
What about upgrading if one finds the allowance isn’t enough? When on one of the hidden plans, is it possible to upgrade to the next hidden one up?
For example, suppose one subscribes to the 2GB of data £5 and finds it isn’t enough; is it possible to move to the 4GB for £6?
I may ask a similar question of other operators. Perhaps this is a subject to discuss on a page of its own, analysing the policies of each provider.
Ken replied:
Hi Dave,
Thanks for bringing this to my attention – this has now been fixed! 🙂
With regards to upgrades, I don’t believe these will be available when you upgrade. If you want to increase your data allowance, you can do this through the My3 app but I believe they’ll only show you their normal plans there.
Ken
Paul said:
Ken
Are there any 3 offers available on PAYG bundles please ? I have already got a 3 PAYG SIM with some credit thereon.
Thanks.
Paul
Ken replied:
Hi Paul,
Thanks for your comment. Sadly, I don’t believe they have any offers running on Pay As You Go bundles. However, if you like, you can sign up to one of their Pay Monthly SIM cards and you can transfer your existing Pay As You Go credit over to it as a credit on your bill. For instance, if you have £30 of Pay As You Go credit, this could pay the first 5 months of your £6/month SIM card.
Hope this helps,
Ken
Paul replied:
Thanks – great suggestion !