What is the best dual-SIM phone you can buy in the UK?
Your buying guide for the best dual-SIM phones in 2018
Dual-SIM smartphones let you use two SIMs in a single phone. Most people who use dual-SIM phones find the functionality useful for mixing work and pleasure, rather than carrying separate phones for their work- and personal contracts. See all phone reviews
Also see: Best Phone Deals
Dual-SIM phones are also useful for maintaining two personal contracts, however, whereby one might offer a good rate on calls and texts, and the other offers unlimited data. Or perhaps you frequently travel abroad, and would like to carry a UK SIM for when you're at home and another that is local to the country you're visiting.
Dual-SIM phones are incredibly popular outside the UK, but for some reason us Brits are being left out of the dual-SIM party.
This is one reason why the Chinese market has become a popular solution for picking up a dual-SIM phone, but there are risks involved - read our advice on buying grey-market dual-SIM phones.
How do dual-SIM phones work?
Something we've noticed when shopping for dual-SIM phones is that the manufacturer very rarely provides any information about the functionality other than it exists. It doesn't tell you how the dual-SIM functionality works in practice, nor whether both SIMs support 4G, or even what size SIM cards they accept.
You can never assume: you'll need to contact the manufacturer or check spec tables, reviews or forums to find out this information. Also see: Best budget phones
In all the dual-SIM phones we've tested both SIMs are on standby at all times (known as dual-standby phones), but you can actively use only one SIM at a time. This means that either SIM can accept a phone call or text at any time, without you having to actively swap between them or reboot the phone.
However, if you get a call on one number while a call is active on the other, it won't start ringing in your ear or give you the option to put the first caller on hold - the call will simply not be successful. Also see: Best kids' phones 2017
What is the difference between Dual-Standby and Dual-Active?
Dual-active SIM phones use two modems and allow you to receive calls on both numbers at once.
If it's you who wants to make a call or send a text, Android has a standard SIM Management menu that lets you specify which SIM should be used for voice calls, video calls, messages and mobile data. You can either specify a particular SIM for each of these tasks, or leave the setting at Always ask.
The data connection is where there seems to be a lot of confusion when it comes to dual-SIM phones. Whereas both SIM slots on some dual-SIM phones are capable of supporting 3G or 4G connections, you can use 4G on only one SIM at a time. Also see: Best smartphones 2017.
Unlike with calls and texts the data connection can't be on standby for both SIMs: you must specify which SIM you want to use rather than select one when prompted.
By default, when you are using the data connection on one SIM and a phone call comes in to the other it will pause the data connection on the first.
Another issue when using dual-SIM phones is where your contacts are stored. We found that by default the contacts from both SIM cards are stored in the phonebook.
If you'd rather see the contacts from only one SIM, tap the three dots icon (within the Contacts app) and choose 'Contacts to display'. You can then select All contacts, Gmail contacts, phone contacts or one of your two SIMs.
1. OnePlus 5T
- Reviewed on: 4 January 2018
The OnePlus 5T isn’t a surprise, both in its existence and the fact it’s very similar to the OnePlus 5. It stands as a reminder that 2017 was the year every company quickly produced a phone with an 18:9 display to make sure its bezels didn’t look outdated on the store shelf.
But OnePlus isn’t on many store shelves given its online retail approach, and its many vocal core fans who bought the 5 will be annoyed by the 5T. OnePlus needed to update its design language quickly to keep up with the wider market where it is yet to make a dent, and the 5T is overall a better device than the 5.
And let's not forget that for £449, the OnePlus 5T is an exceptionally well rounded smartphone. It is at least £100 cheaper than similar handsets, and sometimes close to £300 less.
If you buy into the design (without waterproofing and wireless charging) and price but can accept that the camera isn't top draw and it’ll probably be superseded in six months, then it’s a great choice.
Read our OnePlus 5T review.
2. Xiaomi Mi6
- Reviewed on: 26 May 2017
This really is an amazing phone, and only the Chinese software puts us off recommending it for a UK audience. It is crazy fast, crazy beautiful and crazy priced. If you know your way around Android go and get one, and you won’t be disappointed.
Read our Xiaomi Mi6 review.
3. Xiaomi Mi5s
- Reviewed on: 29 November 2016
We cannot recommend the Xiaomi Mi5s enough. This is the smartphone every 2016 flagship wanted to be, and it comes with a price tag half that of theirs. Fantastic build quality, fantastic performance, fantastic storage, battery and connectivity options - the Xiaomi Mi5s gets a big thumbs-up from us.
Read our Xiaomi Mi5s review.
- Reviewed on: 12 July 2017
The Mi Note 2 was wrongly overshadowed at its launch. This is a gorgeous big-screen Android phone with very decent performance, a great camera and plenty of storage. We'd like to see a Quad-HD screen on Xiaomi's flagship phone, but this one should prove plenty sharp and clear. Google apps are not preinstalled, but there is a workaround if you are happy to do some tweaking.
Read our Xiaomi Mi Note 2 review.
- Reviewed on: 7 November 2017
We remain huge fans of the Mi Mix family, but rather than the revolutionary beast it once was Xiaomi's 'bezel-less' phone has been brought kicking and screaming into line with other Android flagships.
It may have lost some of its wow factor, but in the most part we're pleased with the changes: we love the new design, both smaller and lighter and therefore more manageable than before. We also love the improved connectivity, now with complete UK 4G support.
We don't love the reduction in battery life, though, nor the loss of the headphone jack, and we're not enamoured with the new camera bump.
But the Mi Mix 2 is still a fantastic phone: significantly faster than its predecessor, and much better looking. Better still, it's as affordable as ever, making it a great alternative to other Android flagships - provided you can either live without or cope with having to set up Google services yourself.
In the Mi Mix 3 we would love to see Xiaomi's dual-camera implemented, plus a higher-resolution screen. Waterproofing and wireless charging would also be good shouts.
Read our Xiaomi Mi Mix 2 review.
- Reviewed on: 5 May 2017
Running Flyme OS 5 out of the box, the well-built Meizu Pro 6 Plus is a fantastic Android phone with some seriously good performance, a vibrant and high-resolution screen and a decent camera. Unfortunately, though cheaper than UK flagships, at £399 (before import duty) it’s still too pricey to properly compete with the Galaxy S7 and OnePlus 3T. Neither are we in love with Flyme OS.
Read our Meizu Pro 6 Plus review.
7. Moto G5
- Reviewed on: 12 September 2017
There’s plenty of competition in Android’s budget market, but the Moto G5 is one of the best. The build quality alone feels like it belongs on a much more expensive phone, while the fingerprint gesture controls genuinely improve the Android experience.
The benchmarks and battery hold it back, but they're not unreasonable given the price. You'll find better specs in Chinese phones, but if you don't need a dual-SIM phone and you want the peace of mind of a proper UK warranty, it's a solid choice.
But do check out the G5s as well if your budget can stretch a little.
Read our Moto G5 review.
8. UMIDIGI Z1
- Reviewed on: 26 September 2017
It’s not as fast as its predecessors, with which it shares the same but still just as good-looking design, but we do like the extra battery power and storage space, and the improved cameras of the Z1. We’re also pretty keen on the price - at £139 the UMIDIGI Z1 is a very impressive budget phone.
Read our UMIDIGI Z1 review.
9. Honor 8
- Reviewed on: 5 September 2016
The Honor 8 is a fantastic smartphone, but the price has gone up from the Honor 7. In return for the additional expense you get a fantastic dual-camera, a sleek and stylish design, a faster fingerprint sensor and a beautiful display, which combined make the Honor 8 a worthy competitor to the OnePlus 3.
Read our Honor 8 review.