SMARTY is a low-cost mobile network, owned by Three, offering money back every month for your unused data.

In the UK, SMARTY is a low-cost mobile network, offering SIM-only deals with coverage from Three. The network offers a choice of four data discount plans along with an unlimited data plan.

Most customers of SMARTY will choose one of the four data discount plans: Extra Small (1GB of data for £6.25/month), Small (2GB of data for £7.50), Medium (4GB for £10) or Large (8GB for £15). The plans come with unlimited calls and unlimited texts included, as well as a discount of £1.25 per GB for unused data. Customers wanting unlimited data can choose the £25 unlimited plan.

In this article, we’ll review the SMARTY mobile network, starting with their line-up of 5 SIM-only plans. We’ll then compare SMARTY’s deals to rival mobile networks like giffgaff, before looking at the level of coverage you can expect and how to keep your existing phone number.

Pricing & Bundles

SIM Only Plans

SMARTY offers a choice of data discount and unlimited plans.

SMARTY offers a choice of five SIM-only plans: four ‘data discount’ plans and one ‘unlimited’ plan. All of the plans come on a one-month rolling basis with 3G & 4G coverage from the Three network:


If you choose one of the four data discount plans, the tariff is structured in such a way that you’ll pay a base fee of £5/month for unlimited calls and unlimited texts. On top of this, you’ll then pay a flat rate of £1.25 per gigabyte of data regardless of which plan you choose.

If you choose the unlimited data plan, you’ll pay £25 per month for unlimited minutes, unlimited texts and unlimited data. There are no additional charges for using too much data, but at the same time there are also no discounts available for unused data.

There’s no need to undergo a credit check on SMARTY, as the plans work on a pre-paid basis. You’ll pay for your plan in advance using a registered credit card or debit card, with the top-up being converted automatically into a one-month plan.

Unused Data Discount

One of SMARTY’s unique features is the “unused data discount”. This gives you a cash discount on the following month’s plan based on data that remains unused at the end of your current month’s plan. This discount is offered at a rate of £1.25 per gigabyte, and means you’ll pay the exact same amount regardless of which plan you choose.

For instance, taking an example customer that uses 1.6GB of data per month, the actual price paid will always be £7/month. This is regardless of which plan you choose:

SMARTY Base Plan Actual Data Use Unused Data Unused Data Discount Your Following Month’s Plan
Small Plan
2GB @ £7.50
1.6GB 0.4GB
(2GB – 1.6GB = 0.4GB)
(0.4GB x £1.25 = 50p)
£7 for 2GB
(£7.50 less 50p discount)
Medium Plan
4GB @ £10
1.6GB 2.4GB
(4GB – 1.6GB = 2.4GB)
(2.4GB x £1.25 = £3)
£7 for 4GB
(£10 less £3 discount)
Large Plan
8GB @ £15
1.6GB 6.4GB
(8GB – 1.6GB = 6.4GB)
(6.4GB x £1.25 = £8)
£7 for 8GB
(£15 less £8 discount)

On the Extra Small plan (1GB @ £6.25), you’d have to add a cash top-up to your account. You could then pay for an additional 0.6GB of data at £1.25 per gigabyte (costing 75p). The total cost for 1.6GB of data would therefore be £7 (£6.25 plus the additional 75p).

Because of how this pricing structure works, it can often be advantageous to choose the largest plan. This is especially the case if you’re not sure how much data you need every month. Because of the unused data discount, you’ll only ever pay for what you actually use (but you’ll have more flexibility on how much data you can use on the larger plans).

The unused data discount is calculated based on the number of megabytes you have remaining unused at the end of the month (1MB = 0.001GB). This means you’ll receive a discount for the exact amount of data you have left unused, rather than only in gigabyte increments.

The unused data discount is only available on the Extra-Small, Small, Medium and Large data discount plans. If you’re on the unlimited data plan, you won’t be eligible to receive a data discount.

As of February 2019, SMARTY says their customers have earned data discounts totalling £813,792.

Pay As You Go Rates

All of SMARTY’s plans include unlimited minutes, unlimited texts and an allowance of data that can be used in the UK and when travelling in Europe. The inclusive minutes can be used for calling UK landlines and mobiles (that’s most phone numbers beginning with 01, 02, 03 and 07).

For everything else that’s not included in your allowance, you’ll need to top-up your SMARTY account with a cash add-on. This can then be used to pay for your out-of-allowance usage:

Calling Rates:
Calls to UK landline & mobile Included with base plan
Calls to Voicemail Included with base plan
Calls to International Numbers 3p/minute to £2/minute
Calls to Special Rate Numbers 3p/minute access charge
+ service charge from the company you’re calling
Messaging Rates:
Text Message (SMS) Included with base plan
Picture Message (MMS) Included with base plan
Internet Rates:
Mobile Internet £1.25/GB

It’s not possible to use SMARTY on a purely Pay As You Go basis. You’ll need to maintain an active plan at all times for you to be able to make and receive phone calls.

Comparison to Alternatives

Extra Small Plan

SMARTY’s entry-level Extra Small price plan costs £6.25 per month for unlimited minutes, unlimited texts and 1GB of data. This is a fairly competitive price plan for light mobile users, with very few other mobile networks offering a similar allowance at this price point:

iD Mobile500Unlimited1GB£5.00
1 month
1 month
12 months
1 month

Small Plan

SMARTY’s £7.50 Small plan also compares fairly favourably to rival mobile networks. For a payment of just £7.50 per month, you’ll get unlimited minutes, unlimited texts and 2GB of internet.

On rival mobile networks like giffgaff, you can get a fairly similar offering but without the inclusion of unlimited minutes and the unused data discount. For instance, giffgaff has a £8 goodybag with 500 minutes, unlimited texts and 2GB of data (giffgaff’s coverage comes from O2 rather than Three).

SMARTY’s £7.50 Small plan compares as follows to rival mobile networks:

iD MobileUnlimitedUnlimited2GB£7.00
1 month
12 months
1 month
iD Mobile500Unlimited4GB£8.00
1 month
12 months
1 month
Plusnet Mobile1,000Unlimited2GB£9.00
1 month
Plusnet Mobile500Unlimited2GB£9.50
1 month
To show you the most relevant price plans, 2 similar plans have been hidden. .

Medium Plan

SMARTY’s £10 Medium plan comes with unlimited minutes, unlimited texts and 4GB of internet. Other mobile networks may sometimes offer more data at this price point, but it can vary depending on time-limited promotions.

The following table shows comparable SIM-only deals at the £10 per month price point:

12 months
12 months
iD Mobile500Unlimited5GB£10.00
1 month
1 month
24 months
1 month
ASDA Mobile600Unlimited3GB£10.00
1 month
Plusnet Mobile1,500Unlimited3GB£11.00
1 month
iD Mobile500Unlimited10GB£12.00
1 month
1 month
12 months
ASDA Mobile800Unlimited4GB£12.00
1 month
Plusnet Mobile1,000Unlimited3GB£12.00
1 month
24 months
iD MobileUnlimitedUnlimited10GB£13.00
1 month
To show you the most relevant price plans, 8 similar plans have been hidden. .

Large Plan

SMARTY’s £15 Large plan comes with unlimited minutes, unlimited texts and 8GB of internet.

At this price point, it’s often possible to get better deals on other mobile networks, but this may require you to sign up to a 12-month contract. The unused data discount is also exclusive to SMARTY, and isn’t available on plans from other networks.

One notable alternative is giffgaff’s £15 goodybag (also available on a 30-day rolling basis). For £15 per month, giffgaff will give you unlimited minutes, unlimited texts and 8GB of internet. Once you’ve been a customer of giffgaff for 3 months, an extra 1GB will be added to your allowance each month. This will give you a 9GB monthly allowance.

SMARTY’s £15 plan compares as follows to rival mobile networks:

12 months
1 month
1 month
12 months
ASDA Mobile1,000Unlimited6GB£15.00
1 month

Unlimited Plan

SMARTY is one of four UK mobile networks to offer an unlimited data plan. The following table shows how SMARTY’s £25 unlimited plan compares against rival offerings from giffgaff, Three and Virgin Mobile:

Virgin MobileUnlimitedUnlimitedUnlimited£27.00
To show you the most relevant price plans, 2 similar plans have been hidden. .

giffgaff’s Always-On data plan only offers 4G download speeds on the first 20GB per month. Meanwhile, Virgin’s unlimited data plan is exclusive to customers who have Virgin TV or home broadband. See our full comparison of unlimited data plans for a more in-depth comparison.

You can also see our full listing of SIM-only deals available in the UK.


SMARTY is a SIM-only mobile network, so you’ll need to provide your own unlocked handset to use with the service. You can use any compatible 3G or 4G smartphone, including your existing phone or one that you’ve purchased SIM-free.

If you’re planning to use your existing smartphone, it might be necessary for you to first unlock it before using it on SMARTY. For more information, see our guides to unlocking an iPhone and unlocking a Samsung Galaxy smartphone.

If you’re buying a new unlocked smartphone, there are a number of retailers where you can easily buy a SIM-free smartphone. Our current recommendation for a mid-range and affordably priced handset is the Moto G which is available from around £120 unlocked.

Network & Coverage

3G & 4G Coverage from Three

SMARTY offers 99.8% population coverage on 4G.

SMARTY is a low-cost sub-brand of Three. As Three provides all of the underlying coverage for SMARTY, customers will receive the exact same coverage as they would on Three.

At the time of writing, SMARTY offers 98.3% population coverage on 3G and 99.8% population coverage on 4G. You can check the coverage in your area by entering your postcode on SMARTY’s online coverage map:

Check SMARTY Coverage Map ( →

Like Three, and like all other mobile networks using coverage from Three, SMARTY doesn’t provide any 2G coverage. This means a SMARTY SIM card will not work in a 2G-only handset. You may also have limited functionality when using a SMARTY SIM card in some dual-SIM smartphones.

For more information about coverage on different mobile networks, please see our in-depth guide to mobile phone coverage in the UK.

Wi-Fi Calling and 4G Calling are not currently available to customer to SMARTY.


Tethering or personal hotspot refers to the process of sharing your smartphone’s internet connection with other devices (e.g. with a laptop or tablet). It’s useful for getting a mobile broadband connection on other devices whilst you’re on-the-go: for instance, sending e-mails from your laptop or watching YouTube videos on your tablet.

SMARTY allows the use of both tethering and portable hotspot. This is confirmed in the SMARTY help centre:

You’re entitled to use your data however you like, no matter which of the 3 SMARTY plans you’re on. So you can tether and use your phone as a mobile hotspot with your full allowance if you want to.
The only exception to this is the Unlimited plan and if you’re roaming, where you’ll be limited to 19GB.

For more information, see our in-depth guide to tethering on UK mobile networks.

International Roaming

On SMARTY, it’s possible to use your mobile phone abroad through the international roaming service.

Within Europe, you can use your SMARTY plan allowances at no extra cost (up to 19GB of data per month if you’re on the Unlimited data plan).

Outside of Europe, you’ll need to top-up your account with a cash add-on. You’ll then pay SMARTY’s international roaming rates.

Between September 2017 and July 2018, international roaming was not available to customers on SMARTY. If you joined SMARTY prior to July 2018, you’ll need to make a change to your mobile phone settings to use your SIM card abroad.

Keeping Your Phone Number

If you’d like to keep your existing phone number when moving to SMARTY, it’s a straightforward process to transfer it from your old mobile network.

To do so, start off by ordering a SIM card from SMARTY. It will come with a temporary phone number, allowing you to test out the service before moving your phone number over.

Once you’ve done this, you should request a PAC Code from your old mobile network. This should be provided to you free of charge within 2 hours of your request.

When your SMARTY SIM card arrives in the post, and once you’ve had a chance to make sure everything’s working correctly, you should provide your PAC Code to SMARTY through your online account dashboard. SMARTY will then schedule the transfer of your phone number, normally within 2 working days.

For step-by-step instructions on how to move your phone number to Smarty, please select your current mobile network from the drop-down menu below:

PAC Code Finder: Transfer Your Phone Number to Smarty

Your current network provider:

  More Options

For more information about transferring your phone number between networks, please see our guide to using a PAC Code.

More Information

For more information, please see SMARTY’s official website.

Your Comments 64 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 64 comments from readers. You can add your own comment here.

  • Carol Jackson said:

    Hi I got my SIM from Smarties.. When I put the SIM in my phone it came up saying locked SIM network then underneath for you to put a puk code in. I’ve messaged Smarties on chat.ive emailed them 3 times and had no reply. I’ve had my SIM for a week now and feeling very frustrated that I have been able to use it. I’ve paid 10 pound for SIM that is said to be good yet I can get no help from the company to get it working

  • Hi Ken

    I am looking at using SMARTY to replace a home internet connection. I tried a THREE sim to check speed. It was rapid.

    So I have been looking at getting a 4G router, connecting this to my computer via ethernet, and simply using it as I would a normal connection. Does this count as tethering? I think it does?

    I spoke to customer service. He seemed to be getting confused. He said that I could use the full unlimited package in this way. Then in a different email, to a separate address, the same guy told me tethering was limited to 19GB. Do you think he was confusing this with the tethering and roaming policy?

    Did you try something similar, and was it allowed?


    • Hi Lee,
      Thanks for your comment. You can use a SMARTY SIM card in any device, including in a 4G home broadband router. There are no restrictions on tethering when using SMARTY, so you can use the unlimited allowance as normal through a router (in fact, almost all UK mobile networks have removed restrictions on tethering since an Ofcom net neutrality ruling last year).
      With regards to the 19GB limit, this is how much data you can use at no extra charge when travelling in the EU. It has nothing to do with tethering – I think it’s just the customer services team getting two things crosswired!
      Hope this helps,

  • Can anyone tell me the cost of calls from UK to Jersey in the Channel Islands on a Smarty sim deal & if the same rate applies to Jersey landlines & mobiles?

Load more comments (58)

Leave a Reply

Your e-mail address will never be published. By default, I'll use it to send you an update when there are replies to your comment. However, if you don't want to receive this, you can disable it using the dropdown menu below: