SMARTY is offering an unlimited data SIM card for £25/month with no credit check and a one-month rolling contract.

In the UK, SMARTY is currently offering an unlimited data SIM card. For £25/month, customers can get a plan with unlimited minutes, unlimited texts and unlimited data. There are no speed restrictions for using too much data and the plan is available on a one-month rolling basis with no credit check required.

Order SMARTY Unlimited Data SIM →

In this article, we’ll review SMARTY’s unlimited data SIM card. We’ll start by looking at their unlimited data plan including what you can do with it, both in the UK and when travelling abroad. We’ll also compare SMARTY’s unlimited data SIM card to alternatives from other mobile networks. Finally, we’ll look at the coverage available on SMARTY and how you can keep your existing phone number when joining the SMARTY mobile network.

Unlimited Data on SMARTY

No Download Limits & One-Month Rolling SIM

SMARTY is a low-cost mobile network in the UK, owned and operated by Three as their low-cost subsidiary. The SMARTY sub-brand specialises in one-month rolling plans, giving you a SIM card with no commitment and with no need for a credit check.

SMARTY’s mobile phone SIM card with unlimited minutes, unlimited texts and unlimited data costs £25/month:


SMARTY’s unlimited data plan works on a pre-paid basis so you’ll pay for each month’s usage in advance. The payment will be taken automatically from your registered credit card or debit card unless you disable the automatic renewal in your SMARTY account. For any out-of-bundle usage (e.g. for international or premium-rate phone calls), you can top-up a separate cash balance onto your SMARTY account.

4G Download Speeds

With SMARTY’s unlimited data plan, you’ll get access to full-speed 4G on the SMARTY mobile network.

On SMARTY, there are no speed restrictions for using too much data. This makes it a little bit different to giffgaff’s £25 goodybag with Always-On data which only provides 4G download speeds on the first 20GB per month. On giffgaff, download speeds are restricted to 384kbps (0.4Mbit/s) between 8am and midnight each day once you’ve used 20GB of data.

Whilst SMARTY doesn’t have any speed restrictions for using too much data, it’s worth knowing about their fair usage limit of 1,000GB per month. According to SMARTY, this is used to identify commercial usage of their services:

We have set a usage cap at 1,000GB. When tested, using a mobile for every minute of every day only used around 1,000GB in a month. Setting this cap helps us to identify any commercial use of our services, which is not permitted by our terms and conditions.

Travelling Abroad

If you’re travelling abroad to another European country, you’ll be able to use up to 19GB of data per month at no extra charge. This is possible when travelling to one of the following 34 countries:

Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, French Guiana, Germany, Gibraltar, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Reunion, Romania, Slovakia, Slovenia, Spain, Sweden and Switzerland.

If you’re travelling outside of Europe, it isn’t possible to use the allowances from your unlimited data plan. Instead, you should check the SMARTY website for information about roaming charges. You should also top-up your account with a cash balance before you depart.

If you’re regularly travelling abroad to non-European countries (e.g. the USA, Australia, New Zealand, etc), it might be worth having a look at Three’s Go Roam Around The World offer instead. This will allow you to use your data allowance at no extra charge in 71 destinations, including many destinations that are outside of Europe.

Tethering & Personal Hotspot

On SMARTY, it’s possible to share your unlimited data allowance with other devices through the tethering or personal hotspot functionality on your smartphone. According to the SMARTY website:

You can tether and hot-spot all of your data with no speed restrictions.

It’s also possible to use a SMARTY SIM card in other devices like your tablet, mobile wi-fi router (MiFi) or 4G home broadband router. In fact, you could even combine SMARTY’s unlimited data SIM card with something like a Huawei B525 router to replace your home broadband connection. With an upfront cost of about £120 for the router and then a monthly fee of £25/month, this is competitive in both price and speed against traditional fixed-line fibre broadband services.

Comparison to Alternatives

Three offers unlimited data from £22/month on a 24-month contract.

At present, there are five mobile networks offering an unlimited data mobile plan in the UK: SMARTY, Three, giffgaff, Vodafone and Virgin Mobile.

In general, it tends to be slightly cheaper when you take an unlimited data SIM card from Three. You’ll also get some extra features like Go Roam Around The World (inclusive roaming in 71 destinations). At £25/month, SMARTY’s unlimited data plan is a little more expensive, though it does come with the extra flexibility of being a one-month rolling deal.

12 months
24 months
2Mbps max
12 months
1 month
1 month
2Mbps max
1 month
1 month
10Mbps max
12 months
Virgin MobileUnlimitedUnlimitedUnlimited£27.00
12 months
10Mbps max
1 month
12 months
1 month

Vodafone offers a range of different download speeds across their unlimited data plans. You’ll get speeds of up to 2Mbit/s on Unlimited Lite, speeds of up to 10Mbit/s on Unlimited and uncapped speeds on Unlimited Max.

giffgaff offers Always-On data on their £25 goodybag, giving you unlimited downloads using coverage from O2. However, 4G speeds are only available on the first 20GB per month, with maximum speeds then reducing to 384kbps between 8am and midnight each day.

Virgin Mobile offers unlimited data using coverage from EE. This is available for £27/month on a 12-month contract. You’ll need to be a Virgin TV or home broadband customer to sign up for the SIM card from Virgin.

For more information, see our in-depth guide to unlimited data plans in the UK.

Network & Coverage

3G & 4G Coverage from Three

On SMARTY’s unlimited data plan, you’ll get coverage from the Three mobile network. At the time of writing, this equates to 99.8% population coverage on 3G and 98.3% population coverage on 4G.

You can double-check the coverage in your area by entering your postcode on SMARTY’s online coverage map:

Check SMARTY Coverage Map ( →

SMARTY doesn’t provide any 2G coverage so your smartphone will need to support at least 3G coverage at a minimum. You may have limited functionality when using a SMARTY SIM card in some dual-SIM smartphones.

5G Coverage Launch

Three plans to launch 5G in 25 towns and cities in 2019.

At present, 5G coverage isn’t available to customers on SMARTY.

Three, SMARTY’s parent mobile network, has announced the launch of 5G coverage for August 2019. This will initially roll out in London, followed by another 24 towns and cities before the end of the year:

Birmingham, Bolton, Bradford, Brighton, Bristol, Cardiff, Coventry, Derby, Edinburgh, Glasgow, Hull, Leeds, Leicester, Liverpool, London, Manchester, Middlesbrough, Milton Keynes, Nottingham, Reading, Rotherham, Sheffield, Slough, Sunderland and Wolverhampton.

It is yet to be confirmed whether customers on SMARTY will receive 5G coverage at the same time as customers on Three.

Keeping Your Phone Number

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

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

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

Once your SMARTY SIM card arrives in the post, and once you’ve had the chance to make sure everything’s working correctly, provide your PAC Code to SMARTY by submitting it through your online 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, see our in-depth guide to using a PAC Code.

More Information

For more information on SMARTY’s unlimited data plan, please see their official website.

Your Comments 17 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 17 comments from readers. You can add your own comment here.

  • Leonard King said:

    Hi Ken
    I’ve just this last few days started using Smarty and am very impressed so far. I didn’t realise it was owned by 3, so would this cause a conflict should I decide to use 3’s home broadband (Huawei) router and ditch the land-line, as you can only have one SIM device from the same provider at a time?
    If my iPhone download speeds remain consistently good I suppose I could take advantage of Smarty’s personal hotspot facility for my home broadband and kill two birds etc.

    • Hi Leonard,
      Thanks for your comment. There’s no limit on how many accounts you can have with each provider, so having an active SMARTY SIM card wouldn’t stop you from having another one (nor would it stop you from getting a SIM card later on Three). In fact, if anything, the major providers actually want you to have multiple SIM cards with them so there’s really nothing to worry about here! 🙂

      • Leonard King replied:

        Thanks for that info Ken, I don’t know where I got the idea of being limited to one SIM per provider. I actually thought that there was a technical reason for it. So I can (if it comes to it in year or so) have a 5G home broadband router with 3 & stay with Smarty on the mobile phone.

  • I asked this question before and I will ask it again.
    As Smarty is basically Three, how are they able to get away with offering everyone unlimited data.
    Already I’m seeing a massive deterioration in my 4g speeds. Speeds are erratic averaging between 0 and 4 MBps during the day and jumping to around 48 MBps down at early mornings and pre-dawn.
    Service drops randomly and frequently so much so that I am forced to just access 3g instead. Far more stable.
    I suspect Three giving everyone unlimited data with no tethering or hotspot restrictions is to blame.
    I can understand them giving unlimited data to their Broadband customers but giving it to everyone with a phone plan and with no restrictions is just mind boggling.
    Nobody else is doing it this way.
    I understand their strategy of trying to compete with fixed line broadband providers but at this rate and with them giving everyone with a phone unlimited data,their service will become unusable.

    • Hi Leeman,
      Thanks for your comment. It might be worth getting in touch with Three or SMARTY to see if there are any upgrades planned for your mast, in terms of boosting network capacity. I believe the launch of 5G on Three should lead to a dramatic increase in capacity, but I’m unsure when it is due to launch in your area, and whether there are any upgrades planned to happen before that.

  • I think however if you place the sim in a router, the data is limited to 19gb pcm, however if left in a phone it will be unlimited subject to the 1terabyte condition.

    Is that right?

    • Hi Robert,
      Thanks for your comment. The 19GB limit only applies whilst you’re abroad in Europe. There is no limit on how much data you can use when the SIM card is inside your router.

    • Hi Robert

      As Ken said there’s no data limit when the Sim is in the router. Been using Smarty in a 4G LTE router for around 2 months and in the first month I’ve used just under 100GB without issues.
      I thought there was a fair usage policy of 1000GB but from how I interpreted it Smarty seemed to imply that was not the case according to their response on Trust pilot.

      Wish I had found out about the temporary £18.75 deal before joining Smarty though, £25 still feels slightly steep for use of the internet only.

          • Haha. You could also get in touch with SMARTY’s Customer Support team, and see if there’s anything they can do for you. I suspect it will probably be “no”, but if you threaten to leave and re-join, they might find a way to do it for you 😉

          • Jason N replied:

            Hi Ken

            I’ve had to reply to my previous post because there’s no reply option to your post!?

            Well good news and thanks for the advice. Smarty agreed to apply the 25%
            It seems though that at least one other member received the discount on Trustpilot but not sure how, must have asked for it presumably.

            If anyone who’s on the unlimited plan who became a member before this deal is reading, I would ask Smarty about this before it closes on the 16th July.

          • Hi Jason,
            Thanks for getting back to me! Yes, I think Smarty tend to be pretty good on their customer support, so I’m really glad to hear that they were able to do this for you. I’d definitely recommend anyone who’s already signed up with them to get in touch and to try and get the discount added to your plan as well.

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