SMARTY is offering a £16 unlimited data SIM card in March 2025. There’s no contract, no credit check & 5G coverage from Three.

In the UK, SMARTY Mobile is currently offering an unlimited data SIM card for only £16 per month. It’s a special offer for new customers that sign up in March 2025, and it is reduced from their normal price of £20 per month.

To get the £4 per month discount, you’ll need to order through this special link. The plan gives you unlimited UK minutes, unlimited UK texts, and unlimited data for £16 per month. It’s a one-month rolling plan, with no contract and no need for a credit check. You’ll get 4G & 5G coverage from the Three network.

Get unlimited data for £16 on SMARTY →

In this article, we’ll review SMARTY’s unlimited data SIM card. We’ll start by looking at what their £16 unlimited data SIM card includes, along with the download speeds available and the fair usage policy. We’ll also look at how SMARTY’s unlimited data plan compares to other networks, and how you can keep your current phone number when you move to this deal.

Exclusive Deal: Unlimited data for £16 (no contract)
Reasons To Buy:
  • SMARTY’s £16 unlimited data SIM is one of the cheapest in the market.
  • You’ll get the fastest available speeds on Three, with no fair use limit.
  • Use your plan at no extra cost in the EU (up to 12GB per month).
  • No annual price rises: the cost is fixed at £16 per month for 15 months.
Reasons To Avoid:
Coverage: Three coverage (4G & 5G) – check postcode

SMARTY’s £16 Unlimited Data SIM

In the UK, SMARTY is a low-cost mobile network that’s owned and operated by Three. All of their SIM cards work on a one-month rolling basis, and customers can join SMARTY Mobile with no contract and no need for a credit check.

SMARTY’s flagship plan is their unlimited data SIM card.  It’s normally priced at £20 per month, but there’s a special £4 per month discount (valid for 15 months) when you order through this link. This brings the price of your unlimited data SIM card down to £16 per month:

Network Data Monthly Cost
Smarty
  • Three coverage
  • Unlimited mins
  • Unlimited texts
Unlimited
data
£16.00
per month
1 month rolling
See deal  

On this £16 unlimited data deal, you’ll get all of the following features included:

  • Unlimited data with no fair use limits. There are no hidden fair usage limits on SMARTY’s unlimited data plan, so long as it is being used only “for your personal and non-commercial use”. Prior to 2020, there was a 1,000GB per month threshold that was used to identify possible commercial use of the service. However, SMARTY have said that this is no longer being used.
  • 4G & 5G coverage from Three, with the fastest available speeds. With this plan, you’ll get the fastest available download speeds on Three’s network, without any throttling or speed restrictions. If you’re SMARTY in a 5G area, the average download speed should be around 236Mbps.
  • Roam at no extra cost in the EU (up to 12GB per month). You’ll be able to use SMARTY’s unlimited data plan at no extra cost when you’re abroad in 42 EU destinations. This includes your unlimited minutes, texts and data (up to 12GB per month).
  • Unlimited UK minutes, texts and MMS. Alongside your unlimited data allowance, you’ll get unlimited UK minutes, unlimited UK texts, and unlimited UK picture messages (MMS).
  • Tethering, personal hotspot & mobile broadband. On SMARTY, you’ll be able to use your unlimited data allowance for tethering, personal hotspot and mobile broadband. This is confirmed on the SMARTY website. For this reason, many people use their plans as a backup or as an alternative for home broadband.

It’s also possible to get a data-only version of SMARTY’s unlimited data plan. For all intents and purposes, this is identical to the £16 unlimited data plan, but you won’t get the unlimited UK minutes and texts. As the data-only plan currently retails for £20 per month, there are very few good reasons to choose it at the moment (as you can use the regular £16 plan with no obligation to use the minutes and texts).

If you’re planning to use a SMARTY SIM card for 4G or 5G home broadband, one limitation is that you won’t get a publicly-accessible IP address on it. This is because SMARTY uses strict CGNAT technology, giving you a private IP address that’s unable to accept incoming connections. It doesn’t affect most online activities, but it can stop you from doing things like running a server, using certain P2P apps or playing some online multiplayer games.

Alternatives

If you’re looking for an alternative to SMARTY’s unlimited data plan, it’s also possible to get unlimited data on Talkmobile for £16 per month. This is a one-month rolling plan with access to Vodafone’s 4G and 5G network.

Talkmobile is the low-cost sub-brand of Vodafone, much like SMARTY is the low-cost sub-brand of Three.

Network Data Monthly Cost
Talkmobile
  • Vodafone coverage
  • Unlimited mins
  • Unlimited texts
Unlimited
data
£16.00
per month
1 month contract
See deal  

If you’re living in an area where there is poor coverage from SMARTY/Three, this could be a good alternative.

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

Network & Coverage

On SMARTY’s unlimited data plan, you’ll get 4G & 5G coverage from Three’s mobile network in the UK. At the time of writing, this equates to 99.8% population coverage on 4G. There’s also 60% population coverage on 5G.

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

Check SMARTY Coverage Map (smarty.co.uk) →

You’ll also have access to 4G Calling and Wi-Fi Calling if you have a compatible device on SMARTY.

For more information, see our guide to SMARTY’s network and coverage.

Keeping Your Phone Number

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

Start by ordering your unlimited data SIM card from SMARTY’s website. To begin with, it will come with a temporary phone number assigned to it, allowing you to test out the service before moving your phone number over.

When you’re happy to move your phone number over, you’ll need to get a PAC Code from your old network. This is available through your mobile network’s website or app, or by texting PAC to 65075. You can then submit the PAC Code to SMARTY through your online dashboard. Once you’ve done that, your phone number transfer will normally take place on the next working day.

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

Select your current mobile network:

  More Options

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

More Information

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

Your Comments 59 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 59 comments from readers. You can add your own comment here.

  • Ken said:

    Hi all,
    Just a quick note to let you know that SMARTY have reduced their unlimited data plan to just £15/month. You’ll be able to benefit from this offer for up to 15 consecutive months, and it’s available as long as you sign up before the 4th November 2024.
    I’ve updated the article above to reflect 🙂
    Ken

  • Gary Mackenzie said:

    Smarty have shutdown my SIM as I used 100gb of data a month and that is in breach of their rules.
    Their sims are not to be used as your only broadband source.

    why they sell a WiFi router and SIM package is beyond me, as that router is mains only

    • DT replied:

      I came here to investigate that same use case: I can see in their T&Cs sections 5.15/5.16 they say it’s not for use as a permanent alternative to home broadband (assessed by regularly tethering more than 8 devices, not necessarily quantity of data). So, yes, selling a router package makes no sense for most people! *facepalm* 😉

  • J said:

    I have set my old man up with a b311 & smarty SIM for his home broadband, his area has done away with cheap ADSL offers as it has gone fibre / digital – the prices are upwards on £26 a month.

    He gets great speeds – 50 down, 17up with smarty for £16 a month unlimited.

    so in a nutshell he’s getting much faster speeds than ADSL, £10 a month cheaper than a fibre deal and no contract – win win.

  • Christopher Pugh said:

    I have been having trouble getting both the app and the website to display my data usage. I told SMARTY in April and the problem is still not resolved. Yesterday, September 8, they said that the problesm had been sorted. It has not. I contacted them again today and was asked “Have you activated the SIM”, The SIM was activated nearly 2 years ago. On commenting adversely about the quality of customer service, I have not yet received a reply.

  • Karl Harris said:

    Hi Ken. I am currently with the 3 network an get this unlimited everything deal for 17 pounds a month, this is on a 24 month contract which is due to renewed on September 1st. I contacted them to see if they could match your price they couldn’t. My question is if I come to you on a rolling one month contract will it always be 16 pounds a month or could you increase the price at any point. As I know that three will be 17 pounds a month for 24 months.
    Regards Karl

    • Ken replied:

      Hi Karl,
      Thanks for your comment. I believe SMARTY’s £16 unlimited data offer is guaranteed for 12 months. After that, prices may change, though you can of course change your network at any time.
      Hope this helps,
      Ken

  • Chris said:

    I have a lodge holiday home and there is no way of getting fixed line broadband, can I watch TV through an unlimited data sim by connecting the TV to my phone by using the phone as a hotspot?

    • Ken replied:

      Hi Chris,
      Thanks for your comment. Yes, you should be able to do this, subject to the speeds available at that location 🙂
      Hope this helps,
      Ken

    • Ken replied:

      Hi Rek,
      Thanks for your comment. I believe it does say within the terms and conditions that you need to activate your SIM card within 14 days to get the deal (though I haven’t actually tested it myself to see what happens if you leave it for more than 14 days). Regardless, I’d definitely try to activate as soon as you can to get the benefit of the discount 🙂
      Ken

    • Ken replied:

      Hi Amanda,
      Thanks for your comment. Sadly, I believe this is only available for new SMARTY customers. You can always sign up again as a new customer if you like. However, if you want to keep your current phone number, you’ll need to port it out to another network (such as giffgaff), and then back in to the new SMARTY SIM.
      Hope this helps,
      Ken

  • Daniel Dunn said:

    Hi Ken

    I am going to use this smarty sim in my 4g router. At the moment I am using Giffgaff and the speeds are really bad. O2 coverage check said good signal inside and outside but that is not the case. My question to you is will Smarty give me better speeds?

    • Ken replied:

      Hi Daniel,
      Great question! The speeds will be heavily dependent on coverage and capacity in your area so unfortunately it’s difficult for me to give an answer to this question! The best thing to do would really be to just order a SIM card and give it a go for one month (seeing as you’re not tied in to any contracts). Alternatively, if you already have a SIM card from Three lying around, you can get a pretty good indication testing the speeds with that SIM.
      Hope this helps,
      Ken

  • george Baker said:

    Can I use Smarty in a residential property in Bath centre (a good coverage area) without having a landline to the property?

    Thanks

    • Ken replied:

      Hi George,
      Thanks for your comment. Yes, you can use a SMARTY SIM card in this way to get 4G broadband without the need for a landline. Obviously, it’s important to test it out yourself, however, to see what the coverage & speeds are like where you live.
      Hope this helps,
      Ken

  • john said:

    Hi Ken,
    I am a customer of Smarty and am very pleased with them…so far. The only issue is getting answers from their customer service team. Do you, or anyone, know if I can use a Smarty SIM card in a phone that is locked to the Three network?
    thanks

    • Ken replied:

      Hi John,
      Thanks for your comment. I don’t believe Three have locked any of their phones since January 2014 so I highly suspect your phone isn’t actually locked to Three (and if it is, you can get it unlocked for free from Three). However, if it is, I believe it will probably be fine using a Smarty SIM card inside it.
      Ken

  • Mike said:

    Hello Ken.

    Just found out that Smarty are offering unlimited data for £18 a month for a year for new customers. Offer runs until end of July. For a monthly contract this is good deal!

  • Paul said:

    I am just about to leave GiffGaff in preference to Smarty’s deal.
    But5 thought i would mention, the claim by Giffgaff that their throttled (over-limit) speed is reduced to 384kbps is a bit erroneous of them, as almost everytime i checked my up/down speed, it was RARELY much above 100kbps, and took, for example, facebook, outlook, and even a simple websearch anything up to half an hour to load!
    Really it is just their £20 deal with a pathetic ‘token’ throttled speed once you run over that limit of (now) 80gb!
    And their rather amateur ‘staffing” tend to ALWAYS infer YOU are to blame.
    SO BE WARNED

  • Sabreena said:

    I have a prblm can u help me actually someone is using my smarty dashboard and checking the details about data minutes and texts can u tell me how can I remove my smarty dashboard from other devices I mean log out and scure my dashboard???

    • Ken replied:

      Hi Sabreena,
      Thanks for your comment. Unfortunately, this is a question that’s probably best directed to SMARTY’s customer service team! My thought is that changing the password should normally log out all other devices, but I’m not sure how it’s set up on SMARTY’s end and therefore whether this would definitely solve the issue for you.
      Ken

  • Kev said:

    Hi there. I have just bought a Smarty unlimited data sim. Can I use this sim in any wifi router? I have a spare EE 4G router, will it work in this router? Can anyone recommend a router that I can use to benefit from the Smarty data sim? Thank you

    • Ken replied:

      Hi Kev,
      Thanks for your comment. Yes, you can use Smarty’s unlimited data SIM card in a router. EE’s 4G router should be compatible with the SIM, though you’ll possibly need to get it unlocked first. Alternatively, there are unlocked 4G routers you can buy e.g. from Huawei like the Huawei B525 which is always a very popular option.
      Hope this helps,
      Ken

      • Paul replied:

        WOW! That is REALLY brilliant of Smarty!
        Manyproviders tend to block this form of use, including normal everyday tethering.

        • Ken replied:

          Hi Paul,
          Kind of! However, an Ofcom net neutrality ruling in 2018 made it clear that mobile phone SIM cards can now be used in any type of equipment or device. Therefore, all mobile networks should now be allowing you to do this (though a couple of other networks are trying to workaround it – e.g. O2 says unlimited data SIM cards can only be used a battery-powered device, other networks have a limit on the number of tethered devices, etc).
          Ken

  • Sean said:

    hi Ken i use smarty unlimited data sim in my Zyxel lte4506 4g router and use it as my home broadband, i think its great value at £18.75 i get far better speed than on BT. and the bonus is i can take the router anywhere i go and run it off a power bank. I think smarty will go from strength to strength

    • Jason replied:

      @Sean. This is good to know. I plan using it as my home broadband if it’s any good. Currently with BT on an exchange only line so no hope of a fibre upgrade it seems in the near future tho BT aren’t shy in putting the bill up. Stuck on 16 down and 1 up with some snr tweaks through my billion router. The down speed is bearable but the up speed is a joke in this day and age. As a gamer 1Mbps upload speed barely passes the minimum requirement. Just ordered the Smarty unlimited so I’ll see how it goes in a couple of days. Fingers crossed it’s bye bye BT and your £68 a month bills.

  • Siobhan Henry said:

    Ken, I recently purchased an unlocked Huawei B535 router and a Smarty unlimited data sim. However I cannot get router to work. It works fine with a 3 sim but not Smarty. Do I need to do something special to get it to recognize the smarty sim?

  • William Hewitt said:

    Hi,

    I have been using Smarty for a couple of years now with excellent service throughout the uk.
    My issue is that Smarty does not allow me to use my Iphone tethering function whilst travelling throughout Europe. It works fine in the UK but not EU.

    • Ken replied:

      Hi William,
      Thanks for your comment. Have you checked to make sure you have the latest version of SMARTY’s APN settings? As far as I know, there shouldn’t be any restrictions on tethering whilst you’re travelling abroad.
      Ken

      • William Hewitt replied:

        Hi Ken,

        Yes all my APN settings are correct. I have not been in the EU since September 2019 but this is the last update I had from Smarty. It only applies to Apple devices I think.

        “On Wed, Sep 11, 2019 at 04:05 PM, “Graeme” wrote:
        We’ve identified an issue that’s stopping some customers’ devices from tethering while roaming – this means you won’t be able to use your device as a mobile hotspot with your SMARTY SIM. We’re working with device manufacturers to fix it, but unfortunately it’s taking longer than we’d like.”

        • Ken replied:

          Hi William,
          Interesting – I wasn’t aware of this limitation. Thanks for bringing it to my attention – fingers crossed they solve it very soon!
          Ken

      • Paul replied:

        So far as i am aware (And i am VERY new to their service) is you need to arrange or change settings for, for instance, travel to EU from UK.
        And certain functions MAY NOT be available, as they NEED to slap on a ”fair use” limit for such purposes, and is likely so that THEY themselves can afford to provide you with that serrvice, since, after all, they are otherwise providing you with a cheap service.
        SO seems sort of fair enough to me.
        But i do suspect in time, this will change as the technology and ways of using it change and eveolve.

  • Dee Davis said:

    Hi Ken,
    I activated my smarty sim 4 days ago and whilst I’m outside (even on my doorstep) I get full coverage, as soon as I step inside I get 0-2 bars.

    I have contacted them about this via email and got a response stating that there is an outage in my area, but then I check there checker it states their is no problems. I’ve left a perfectly good network to a network that can’t provide coverage.

  • Mike said:

    Hi everyone. Smarty has a special offer on their Unlimited plan. Starting from today until the 28th August the price is £18.75/month (25% off the normal £25/month).

    Mike

    • Ken replied:

      Hi Mike,
      Thanks for the heads up about this – it’s fantastic to see that they’ve brought this offer back! I believe it’s valid until the 28th August 2019, and you’ll need to activate before the 3rd September to be eligible for the discount. I’ve updated the article above to reflect this 🙂
      Ken

  • 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.

    • Ken replied:

      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! 🙂
      Ken

      • 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.
        Win/Win.

      • Leonard King replied:

        Hi again Ken
        Reason I’ve come back to you on this is because Chinese audio manufacturer Hiby is going to be releasing a DAP (model R8) which has a slot for a SIM so that users do not need wireless for streaming music. Great idea and very appealing to me. Presumably a purchaser would already have a SIM for their mobile, so a second one would be a new separate paid for account I suppose which makes it less appealing.

        • Ken replied:

          Hi Leonard,
          Thanks for letting me know about this! Is the built-in SIM card slot so you can stream audio over a 3G/4G connection? Like you said, it could potentially be useful for some (though most people are probably better off getting a 4G home broadband router, or perhaps something like the Huawei AI Cube which can function as a smart speaker).
          Ken

          • Leonard King replied:

            Hi Ken
            Yes, that’s the idea, to stream audio over 4G from the likes of Qobuz, Tidal & Spotify. It would benefit people who like to listen to their music while they’re out & about, as at the moment wireless restricts them to listen at home or in wi-fi spots. I get by on my iPhone Special using 4G, but it doesn’t have the most up to date bluetooth codecs ie LDAC, APTX-HD, and most DAPs do have these built in.This model isn’t released yet but is due at any time. I’m sure you’ve googled it by now anyway.
            All the best, Leonard

  • Leeman said:

    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.

    • Ken replied:

      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.
      Ken

  • Robert G said:

    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?

    • Ken replied:

      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.
      Ken

    • Jason N replied:

      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.

          • Ken replied:

            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 😉
            Ken

          • 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.

          • Ken replied:

            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.
            Ken

    • Ken replied:

      Hi Mo,
      Great question! Yes, I’m not sure that I’m able to remember an unlimited everything plan ever being sold for less than £18.75! So it could certainly turn out to the be the cheapest ever (though it’s possible that someone with better memory will be able to recall something!).
      Ken

      • Paul replied:

        Three’s old ‘One’ plan was £15 a month and was also unlimited everything but on a monthly rolling contract.
        This Smarty deal is better because it’s pre pay with no credit check.

        • Ken replied:

          Thanks Paul! I knew there was someone out there with better memory than me 😉 I remember The One Plan at £25/month, but don’t quite remember it dropping down in price to £15! At one point, I think Three were also offering unlimited data for £12.90/month, but that didn’t come with unlimited minutes (and also, I think tethering was excluded).
          Ken

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