• The benefits and availability of Dual SIM smartphones

    By Richard , September 4, 2016 - Leave a comment

    What is Dual SIM and is it for me?

    Dual_SIMThe answer to this question is surprisingly more complex than you might initially think. For many in the UK Dual SIM may be a term you’re not familiar with. This is because in the UK most phones sold in mainstream stores only have a single SIM slot.

    If however you’re one of our Asian customers, you’ll probably be wondering how someone could survive with only one SIM card!

    Reasons for having Dual SIM

    Having a second phone number might seem like a reason in and of itself. But why might you want a second number? Isn’t one enough?

    There are a number of practical uses for a second phone number so let’s take a look.

    Dual SIM Smartphones | Clove Technology

    Difficulty moving between providers

    As you would expect there are different requirements around the world in regards to network compatibility. This is often why dual SIM slot phones appear in some countries more than others.

    In some countries in the past it has been difficult to reliably change between providers. One solution to this was to sign an agreement with a new provider and use the 2nd slot!

    In the UK we have for a long time enjoyed the ability to freely move between mobile operators. We can also easily take our current number with us.  This has been part of UK law since 2003, and has meant that it has been fairly easy to move between mobile providers.

    This type of legislation has only recently been introduced in some countries, or in some cases not at all. So when customers in these areas have moved to a new network provider, they have to get a new card and contract. To make sure people can still contact them using their old number, they need to keep their existing SIM card running.

    Issues with coverage

    Another problem and reason for needing Dual SIM are issues of coverage.

    Due to the size of some countries there is no one mobile network which has complete coverage. Even in heavily covered countries such as the UK this is still an issue in rural areas!

    Having two SIM cards allows you take advantage of two network providers that may be available in different parts of the country. Although only larger countries in theory have this problem, I imagine many of our readers will no doubt comment that mobile coverage is not perfect in the UK.

    Keeping work and home separate

    Another reason for Dual SIM is wanting to keep your home life and work separate. This is particularly important for anyone who runs a business from one phone.

    Having two SIM cards lets you keep calls and messages for two numbers separate. So you can give out your numbers to the appropriate people. Depending on the phone you can set it to prompt which number to call out on every time, or have defaults. For instance all outgoing calls on SIM 1 and all text messages on SIM 2.


    Dual SIM Honor 7

    There are of course other reasons for needing dual SIM card slots, these are just some examples. Dual SIM phones are a great way to make sure you are constantly available and easy to contact.

    Dual SIM Smartphones | Clove Technology

    So are all Dual SIM phones the same?

    There are in fact two main versions of Dual SIM phones ‘Passive’ and ‘Active’.

    Passive Dual SIM

    Motorola Moto G4 Dual SIM UK
    The Moto G4 is an affordable Dual SIM Standby phone available in the UK for just £160

    ‘Passive’ (standby) is when a phone has a single, shared antenna for both SIM cards. As the name suggests both SIM cards spend most of their time being in a passive standby mode, waiting to be used.

    When you start using one of the SIM cards for either voice or data, the other automatically becomes inactive. Only when you have finished using the first SIM card can you start using the second.

    This means you are not able to simultaneously download data using one SIM card while making phone calls with the other. At first this does seems limiting, but in practice is unlikely to cause too many issues. Particularly as if a line isn’t available to accept a phone call, it is usually diverted to voicemail automatically by the network provider.

    This is the more cost-effective solution for consumer Dual SIM smartphones, so by far the more common version you will see available.

    We can now offer this type of Dual SIM phone from a variety of manufacturers including Motorola, Huawei, CAT, WileyFox, RugGear and Microsoft to name a few.

    Some of the top Dual SIM standby devices at Clove include the Moto G4, Cat S40, Honor 7 & Honor 5X, Wileyfox Swift and Microsoft Lumia 650.

    Active Dual SIM

    ‘Active’ refers to phones which benefit from having two antennae, one for each SIM slot. This means you can simultaneously use the two SIMs. For instance downloading content on SIM1, and making a phone call on SIM 2. You can even have two conversations, switching the calls and putting one on hold.

    There are some disadvantages with this type of Dual SIM phone, the most obvious being cost. There is an extra cost in having two antennae built in to the phone. You also have increased battery consumption, as the power draw for cellular connections is effectively doubled.

    Finally there is the problem of availability. In countries like the UK they are almost impossible to source. For instance HTC released a Desire 600 with Dual Active SIM card slots, but this was never available in the UK.

    Generally if you specifically need an active Dual SIM phone you might sacrifice high end specifications, or buy from a brand you are not familiar with.

    Other Things to Consider

    dual-simWhen buying a Dual SIM phone we would recommend checking if both slots can use 3G/4G connections.

    Not all phones have the this functionality available on the second SIM slot. Many cheaper Dual SIM phones only allow data on one SIM card and just calls/texts (2G) on the second.

    Also many manufacturers combine the SD card and second SIM card slot to create a hybrid slot. This is typically done to save on space, when manufacturing a smooth, slim phone. This can help improve looks, but again limits functionality, as with this setup you need to choose between a second SIM card or expanding storage with an SD card.

    Finally some basic setup is necessary to fully take advantage of the dual SIM capabilities. To make sure data connections and phone calls use the SIM card you prefer, you will need to manage your phone settings carefully.


    There are some disadvantages with using Dual SIM, but for most people who need this type of phone the benefits are far more important.

    You will be able to manage your calls and get the coverage you need in areas of poor reception. An increasing number of manufacturers now offer this type of phone.

    Here at Clove Technology we offer a wide choice on our website. As we mostly source UK stock, some of the major brands are missing from the list, however in the future this feature will be available on more phones giving more choice to customers.

    Dual SIM Smartphones | Clove Technology


    Keeps the computer systems running here at Clove, whilst dealing with the more technical queries that we receive from customers. A keen PC gamer, Richard often spends his weekends beating the competition in online games or re-building his super computer. He's also in to kickboxing and salsa dancing, Richard is a man of many talents.


  • I have a dual sim phone (Oneplus 3) and find the dual sim really useful. I have an EE card (excellent for coverage and high speed but data expensive/limited) and a 3UK card (Good coverage and good speed “all you can eat data”) – I therefore generally have both sims enabled for incoming calls, can selected the card to use for calls/message “on the fly” and generally have only the 3UK card enabled for data as I then don’t have to worry about any data costs. In addition, with 3UK have “feel at home” which gives me cost-free roaming in around 42 countries including the USA, almost all of Europe, Australia etc, (I think its 42 countries in total) The 3UK sim only (feel at home/all you can eat data) costs me around £15 a month which is definitely cheaper than going over my data limit on the EE card and no wqrries about roaming,

    Dual-Sim was not something I was looking for but having used it and found it so useful, I now wouldn’t buy a phone without dual-sim. I used to be a Samsung owner (various Galaxy and Note models) and can’t understand why their dual-sim versions are not available in Europe. It can only cost a few pence for the extra sim-slot and Android properly supports simultaneous dual-sim usage.

    I suspect we will see more more phones/tablets with dual-sim as people realise just how useful it can be. Far easier than having two phones or using a clonky sim adaptor which onltyy enables one sim at a time.

    Hope this has been usewful info and many thanks to Clove for their continued blogs/news – I used to be a regular customer until I found the Oneplus dual sim phones. Maybe I’ll be back if other manuafacturers see sense!

    • Good to see you back, even if you aren’t buying from us any more!

      I agree dual SIM is becoming a more requested feature and has a number of uses even for those who may not be running businesses or travelling.

      You’ve hit the problem on the head though by saying you use two networks. That’s exactly the reason why big names such as Samsung don’t offer their dual-SIM phones here. They enter into big contracts and deals with the operators in the UK and other major EU markets (Germany, France, Italy etc.). That said, we do sometimes see dual SIM stock from Poland, Czech Republic etc. If we get the chance we’ll try to bring the big name’s dual SIM models here, but only if we can guarantee warranty support.

      It’s the networks that don’t like there being an extra SIM slot – remember the likes of Vodafone, O2, EE etc. all like to flash the phones with their own software and lock them down. There would be untold confusion if the average user on the street saw they had a second SIM but the phone was locked. These big companies are also responsible for the majority of sales. We and other independents do enough to count in talks with manufacturers, but we’re still a small percentage of sales in comparison to the high street names.

      There is an argument for SIM free retailers like us having separate SKUs, but then the product managers / marketing people have to manage another whole range of SKUs and sales figures for what is a niche market.

      Basically it’s a lot of politics and corporate nonsense! We are seeing more dual SIM phones from the up and coming brands though. You mention OnePlus – excellent phones and I might get one myself! We’ve also seen Honor (an offshoot of Huawei), Lenovo from China, CAT, Wileyfox and some of the Microsoft Windows phones have success with dual SIM in the last year.

      Alongside OnePlus, I think Honor and Lenovo have the best chance of getting some market share in the UK based on dual SIM alone, as they offer some very nicely made devices with decent specs.

  • I bought a CAT S60 from Clove – It’s Dual-SIM but there’s only the one set of 3G circuitry – so you cannot use two ThreeUK SIMs (3G/LTE only) – be warned! I had to use Vodafone for second SIM.

    • Hello Cliff, if you look into it, you’ll probably see that most dual SIM phones only have 3G data on one card, with the other being 2G (voice/text) only. This will affect Three customers, as they turned off any 2G sharing they had woth other networks a few years ago.

      Some newer dual SIM phones have 3G available to either card, however you can only have one active for data at any time (you choose in the settings). I think this is how the S60 works, although I may be mistaken.

      I am yet to find a standard consumer phone in the UK that will allow two simultaneous 3G data streams.

  • Dual SIM phone should be the base model, but note that some phones though it comes with 2 SIM slot the second is a SIM cum Micro SD slot. So if you wish to use a Micro SD card for portable storage, you will have only one useable SIM.

    But nowadays with 32GB or 64GB onboard memory, SD card may no longer be a necessity. For me, 32GB is good enough for work, personal and games. Unless you are a real selfie addict then SD card is a must.

    Dual SIM will definitely allow users to benefit the best plan either data or voice base on the service selected within one country.

    Also in Asia due to geographical nature being in close proximity, you could stay in one country and work in another. I use to commute between neigbouring country in Asia and you can see users still switch SIM card once they cross the border, but with a dual SIM, you are all set to stay connected.

    BTW, love reading your blogs.

    • These are very good points Azmi. The combined SIM / SD card slot can be frustrating on some of the cheaper phones with low storage as it makes you choose which phone function to keep.

      Switching countries is also a great use-case. In the UK there are also lots of new immigrants or workers from around the world with family and friends in other countries. It can be useful for them to keep a second SIM installed which has good international calling rates (Lebara or similar). This is a lot easier than swapping between SIMs when regularly calling and sending messages to contacts in the UK and other countries.

  • Good article.
    I interested in the possibility of buying a “disposable” sim card when I travel abroad in Europe for data as it is clear the likes of EE are ripping off customers for data.
    I know that this is difficult in some countries such as Germany – maybe someone has done research into this?

    • Hi James, I wouldn’t say I’ve “researched” it, but I do know that a few UK providers have favourable rates for European roaming. There are also laws coming into place to abolish any extra fees.

      I use Three and they offer a good service for many international destinations. There are also networks that specialise in roaming and international charges. I’ve never used them but I know Lebara are popular.

      Finally, getting hold of a PAYG SIM in each country you travel may also be an option. The convenience / cost of this against sticking with one provider and roaming is something you would likely need to spend time looking at yourself.

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