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

In the UK, SMARTY is a low-cost mobile network, offering SIM-only deals with coverage from Three. Having originally launched in September 2017, the low-cost sub-brand of Three promises to offer a “simple and honest” service.

SMARTY’s service revolves around a choice of three SIM-only plans: Small (2GB of data for £7.50/month), Medium (4GB for £10) and Large (8GB for £15). Customers get unlimited calls and unlimited texts included in their plan, as well as a discount of £1.25 per GB of unused data.

In this article, we’ll review the SMARTY mobile network, starting with their line-up of 3 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 three SIM-only plans, all of them on a one-month rolling basis with coverage from Three:


The way SMARTY’s tariffs are structured and calculated are that you pay a base fee of £5/month for unlimited calls and unlimited texts. You’ll then pay £1.25 per gigabyte of data on top of this, regardless of which plan you choose.

There’s no need to undergo a credit check on SMARTY, as the plans work on a pre-paid basis. You’ll pay from a registered credit card or debit card, with this top-up being converted 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 your following month’s plan based on data that remains unused at the end of your 30-day plan. This discount is offered at a rate of £1.25 per gigabyte, and essentially means you 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)

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 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 unused, rather than only in gigabyte increments.

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 allowances, 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

Small Plan

SMARTY’s £7.50 Small plan compares fairly favourably to rival mobile networks. For a payment of just £7.50/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 usually without the inclusion of unlimited minutes and the unused data discount. For instance, giffgaff has a £7.50 goodybag with 250 minutes, unlimited texts and 2GB of data (coverage comes from O2 rather than Three).

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

iD Mobile1,200Unlimited2.5GB£7.00
ASDA Mobile600Unlimited3GB£10.00
Plusnet Mobile1,500Unlimited2GB£10.00

Medium Plan

SMARTY’s £10 Medium plan comes with unlimited minutes, unlimited texts and 4GB of internet. Other mobile networks may sometimes offer slightly more data for £10, but on time-limited promotions. The following table shows comparable SIM-only deals at the £10 per month price range:

iD Mobile300Unlimited9GB£10.00
ASDA Mobile600Unlimited3GB£10.00
Plusnet Mobile2,000Unlimited3GB£12.50

Large Plan

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

At the time of writing, slightly better deals are available on other mobile networks, but may require you to sign up for a 12-month contract.

Alternatively, giffgaff has a £15 goodybag (30-day rolling deal) with unlimited minutes, unlimited texts and 8GB of internet. Once you’ve been a customer for 3 months, an extra 1GB will be added to your allowance each month giving you 9GB of data.

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

iD MobileUnlimitedUnlimited8GB£15.00
ASDA Mobile1,000Unlimited6GB£15.00

For more information, 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 may 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 97% population coverage using the Three network for 3G and 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 97% population coverage across the UK using Three’s 3G and 4G network. 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 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.


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 your other devices connected 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.

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

International Roaming

On SMARTY, it’s now possible to use your mobile phone abroad through an international roaming service. You can use your SMARTY plan allowances at no extra cost when travelling within Europe. 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.

Prior to July 2018, international roaming was not available to customers on SMARTY. If you had joined SMARTY prior to this date, you’ll need to make a change to your 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 38 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 38 comments from readers. You can add your own comment here.

    • Hi Debra,
      Thanks for your comment. Technically, SMARTY works on a pre-paid basis with you just paying for 30 days usage each time. Therefore, there’s no need for you to give any notice – you can simply stop using the service when your bundle comes to an end.
      Hope this helps,

  • What an utter rubbish network.
    It either works out of the box or you are stuck with rubbish customer service – there is no way to actually talk to a person when this network fails.

    Not only is there nobody to talk to but the rubbish ‘chat’ ceases at 8. Though in fairness if you are ‘chatting’ to people who know nothing during the day I think you can reasonably assume they would be equally useless in the evening so I guess it wouldn’t serve a purpose.

    I ported to this rubbish network a few days ago and it worked for a day. Now does not work in iPhone and customer services are useless. Just get fobbed off with assurances the matter has been escalated. Well I need a network to use – I can’t use ‘assurances.

    There’s often a reason things are cheap – and this MVNO is a prime example of that.
    There’s no commitment as such but leaving won’t get me the deal I left for SMARTY and this rubbish service (or non service) has already cost me money to set up which won’t port across.
    Nice little scam then really.

    Avoid like the plague.

  • Switched to Smarty from Vodaphone as they are miles cheaper. So far it’s been really good with no signal problems and pretty fast 4G data.

    And as you get money off your bill each month for any data you don’t use if you switch off mobile data and don’t use it you basically get a phone with unlimited calls and texts for only £5 per month! Bargain!

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