Three mobile broadband review

samantha smith
By Samantha Smith

three mobile logo

THREE are well known for their generous mobile phone data allowances, but how do their dedicated mobile broadband plans stack up?

We'll start by looking at their data SIM plans: these form the backbone of their standard mobile broadband service, whether we're accessing it through tablet or iPad, or a traditional mobile broadband device.

Quick jump menu
Data SIMs
  • PAYG
  • Pay monthly
  • Mobile broadband devices
    Tethering on Three
    Coverage and speed

    Those wondering if a data SIM is really necessary may want to skip ahead to learn about tethering with Three.

    Data SIMs from Three

    The big selling point for Three's data SIMs is the fact that they can all be used with the network's advanced roaming service, Feel At Home - giving users data roaming for no extra cost in 42 international destinations.

    Pay monthly customers don't need to do anything to feel the benefit; pay as you go customers will need to buy a data add-on with their top up credit first.

    Pay as you go data SIMs

    Each of Three's PAYG data SIMs comes with preloaded data, but the amount and how long it'll last for depends on which of the plans we choose:

    Plan Preloaded data Upfront cost
    three Data Reward 1GB
    Valid for 30 days
    three Broadband - Pay as you go + 3 3GB
    Valid for 3 months
    three Broadband - Pay as you go + 12 12GB
    Valid for 12 months

    People signing up for the Data Reward plan are encouraged to register their SIM on site, which will trigger the reward part of the tariff: a free 200MB of data every month.

    If that's not enough to keep them going, they can top up with as little as £2 of credit, or in multiples of £5 up to £50; customers with the other two plans can only top up in multiples of £10 up to £50.

    In either case, as long as the account remains active the credit will never expire.

    As mentioned above, pay as you go users will need to buy an add-on to benefit from Feel at Home. Which add-ons are available depends on whether we have a Data Reward plan or a "Broadband +" SIM.

    Data Reward add-ons:

    Add-on Price Data lasts
    three 2GB data add-on £15 30 days
    three 5GB data add-on £20 30 days
    three 10GB data add-on £25 30 days

    Customers with this plan should note that their free 200MB will be used before their add-on data.

    Broadband + add-ons:

    Add-on Price Data lasts
    three 500MB data add-on £2.99 1 day
    three 1GB data add-on £10 30 days
    three 3GB data add-on £15 30 days
    three 7GB data add-on £25 30 days

    With the exception of the 500MB add-on, customers can buy but not activate any of the add-ons listed above for up to 90 days, allowing us to queue them up if needs be.

    The 500MB boost activates immediately and expires once used up or at midnight on the day of purchase, whichever comes first.

    Pay monthly data SIMs

    As with Three's mobile phone SIMs, pay monthly data SIM customers can choose between signing up for a year or for a month at a time; the latter cost £2 more per month than their yearly equivalents:

    One month data SIMs

    Data Monthly price
    three 2GB £10
    three 5GB £15
    three 15GB £20
    three 20GB £23

    12 month data SIMs

    Data Monthly price
    three 1GB £7.50
    three 2GB £8
    three 5GB £13
    three 10GB £15
    three 15GB £18
    three 20GB £21

    Extra data

    Anyone who goes over their allowance has two choices: pay as they go for data, or buy an add-on.

    Extra data Price
    three Pay as you go 1p per MB
    three 1GB £5
    three 5GB £15
    three 10GB £20

    Users can only buy one add-on per billing cycle; they'll lose any unused extra data at the end of that month.

    Tablets and iPads

    Three offer a small but select range of tablets and iPads on both pay monthly and pay as you go terms.

    Those looking at a PAYG tablet are limited to a choice of iPads (Mini, Air and Pro), a couple of budget Android tablets, or the Amazon Fire Kids Tablet. Going for a pay monthly tablet plan adds a couple of mid-range Androids and the Samsung Galaxy tablets to the line up.

    Pay as you go customers will need to pay for their device in full upfront; pay monthly prices range from nothing to £99 upfront, followed by monthly bills from £12 to £42 depending on the device and data plan we choose.

    Mobile broadband devices

    Online, on the go
    Three's mobile network in detail
    Which network offers the best coverage?
    Three Home Signal reviewed
    Our guide to unlimited mobile data
    Has tethering killed the dongle?

    With the exception of the 1GB pay monthly tariff, all of the SIMs above (PAYG included) are available with one of Three's dedicated mobile broadband devices.

    There's a choice of dongle or portable hotspot: the latter are more flexible as they can connect up to 10 devices at once (as opposed to just one) and are easier to use with devices that don't have standard USB ports.

    Whether it's a dongle or mobile wi-fi we're after, it's worth being aware that not all of them are 4G compatible. The 3G-only dongle and mi-fi device are both about £2 cheaper per month than the 4G devices, but the "advanced 3G" they offer is no substitute for a full 4G connection.

    Pay monthly deals are available on one, 12- or 24-month terms. There's no upfront charge with any of the 24-month deals; expect to pay a higher upfront fee the shorter the contract term.

    The pay as you go prices listed below are based on the 1GB Data Reward plan listed above; pay monthly deals start with a minimum of 2GB per month.

    Device Pay as you go Pay monthly
    Upfront price Monthly price
    three ZTE MF730M dongle (3G only) From £19.99 upfront From £0 to £19.99 From £8 to £23
    three ZTE MF823 4G dongle From £29.99 upfront From £0 to £29.99 From £9 to £23
    three Huawei E5330 Mobile wi-fi (3G only) From £39.99 upfront From £0 to £29.99 From £8 to £23
    three Huawei E5573 4G Mobile wi-fi From £59.99 upfront From £0 to £39.99 From £9 to £23
    three Huawei Road-fi From £59.99 upfront From £0 to £49.99 From £9 to £23

    For the most up to date devices and tariffs available, check our comparison table here.


    Three have chopped and changed their minds about allowing tethering, and to what extent, numerous times in the past, but in April last year they raised the maximum tethering allowance to 30GB a month.

    That means new customers with a smaller data allowance can use the lot for a personal hotspot if they wish, while those with one of Three's 30GB or All you can eat mobile plans have a larger mobile broadband allowance than some capped fixed line deals offer.

    There are two major limitations to bear in mind when looking at tethering with Three:

    The need to sign up for an Advanced tariff isn't that much of a limitation: there are 17 plans to choose from, ranging from 500MB paired with 200 minutes of data up to all you can eat calls, texts and data, with each available on one or 12 month terms.

    To keep things simple, we're only showing the 12-month plans with unlimited calls and texts below; one-month contracts cost another £3 on top of the prices shown.

    Advanced SIM-only plans with unlimited calls and texts

    Data Price per month
    three 1GB £16
    three 4GB £21
    three 8GB £24
    three 12GB £27
    three 30GB £30
    three All you can eat £33

    There are cheaper tariffs available with smaller monthly call allowances - see our full review of Three's phone network for details.


    Three are the UK's smallest mobile network, but they can still offer wide ranging coverage: according to Ofcom 87% of UK premises had good 4G data coverage indoors by the end of 2016 and 97% had a good data signal outside.

    Furthermore, as we've explained in greater detail in our operator review, Three cover more of the motorway and A&B road networks than rivals O2 and Vodafone - meaning that their mobile broadband is much more likely to be genuinely mobile.

    Connection speed

    According to OpenSignal data published in late 2016, Three offer the fastest 3G connections in the UK, at an average of 6.1Mb; they're second only to EE for average 4G download speeds:

    Average download speed
    3G 4G
    three 5.5Mb 28.0Mb
    o2 4.1Mb 16.2Mb
    three 6.10Mb 24.5Mb
    vodafone 4.8Mb 18.0Mb

    SOURCE: Opensignal State of Mobile Networks report 2016. Available here.

    The bad news for Three customers is that according to the same data, they have a 4G connection less than half the time they're in a 4G area; by comparison O2 and Vodafone users can expect to connect to 4G about 60% of the time.


    If we need to have a guaranteed mobile broadband connection wherever we go - including as far afield as New Zealand and the USA - Three are a solid bet.

    Where we can connect to the 4G network we'll get a connection that can rival a fixed ADSL line - but their network capacity means we may find ourselves relying on their 3G data network more than we might wish.

    And while Three's data SIMs are competitive enough, they're not as impressively priced - or generous in terms of allowances - as their mobile SIMs; tethering could be a seriously attractive alternative.


    4 September 2017
    Jack Drennan

    I have the home fi system. Can I use the all you can eat data sim or 100 g?

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