Technology Explained

What Are Dual SIM Phones? Do You Really Need One?

Megan Ellis Updated 21-11-2019

Dual SIM phones come with a variety of benefits, making them a must-have for many people. However, not everyone understands what dual SIM means or how dual SIM phones work.


We’re here to explain everything you need to know about dual SIM phones, their benefits, and how eSIMs fit into this picture.

What Is a Dual SIM Phone?

dual sim phone slots

Dual SIM phones support the insertion and use of two SIM cards on a single device. This differs from a single SIM device, which only has a slot for one SIM card. Of course, you’ll need an unlocked phone to take advantage of the dual SIM feature if it’s supported. And that’s one of the top reasons to buy an unlocked phone 5 Reasons You Should Get An Unlocked Phone You've seen an unlocked phone for sale, but what does this mean? What are the benefits of an unlocked phone? Read More .

The majority of dual SIM phones have active dual SIM functionality. A dual SIM phone can support two active SIMs at the same time, without requiring you to remove and swap SIMs to change phone number.

This means you can receive calls and texts from both lines. You can also usually adjust which SIM is your primary data or voice call card. Some dual SIM phones even support the ability to hold a single conversation with two callers on two different lines.


Meanwhile, the other type of dual SIM phone is a standby dual SIM device. Standby dual SIM devices require you to switch between SIMs in your device settings to activate them. Your phone only connects to one network at a time, so you won’t receive texts or calls for both at the same time.

There are also dual SIM smartphones that support the addition of either a second SIM or a microSD card—not both. This is a limited type of dual SIM functionality seen on older smartphones that means you have to choose between a second SIM or extra storage.

What Is an eSIM?

A more recent type of dual SIM phone is one that supports an eSIM. An eSIM, or embedded SIM, is a built-in microchip that acts as an electronic (rather than physical) SIM card. Since it enables remote SIM provisioning What Is a SIM Card and What Does It Do? What is a SIM card and why is it so important? It connects you to your carrier network, stores contact information, and more. Read More , an eSIM does not need to be swapped out when changing carriers. Rather, these embedded SIMs use software to load profiles and mobile plans from your mobile operator.

While eSIMs can completely replace the physical SIM card in a device, they are also used in dual SIM devices. For example, the iPhone XS, iPhone XS Max, and iPhone XR smartphones feature a dual SIM setup with a nano-SIM and an eSIM.


However, due to the inconsistent adoption of eSIM technology by manufacturers and mobile carriers this setup is not widespread yet. Most dual SIM devices still use two physical SIM cards. It is likely that more dual SIM devices featuring an eSIM will appear in the future as the technology spreads.

You can find out more about how to use and set up an eSIM in our guide on the topic.

Dual SIM vs Single SIM: The Benefits of Dual SIM Phones

dual sim galaxy note 10 smartphone.jpg

There are a variety of benefits to having a dual SIM versus a single SIM phone. In fact, many consumers rank dual SIM support as an essential feature for their smartphones.


Here are some of the benefits of dual SIM phones over phones that only support one SIM card…

Two Numbers on One Phone

Dual SIM phones allow you to use two different phone numbers on a single device. This is useful for people who may have a personal and work number, but don’t want to use two different devices.

Getting the Best Carrier Deals for Data and Calls

A dual SIM phone lets you take advantage of the best deals when it comes to carriers. Often you will find that one carrier has great data rates, while another has better voice call or overall bundle deals.

Using a dual SIM device lets you take advantage of both deals. You can use one SIM for your data bundle, and another for other bundles.


Since dual SIM phone settings allow you to set your primary call and primary data SIMs, it’s incredibly easy to use this approach.

Keeping Your Old Number Without Needing to Port

If you don’t want to go through the hassle or cost of porting your old number to a new carrier SIM, you can always use a dual SIM device. Depending on your contract terms, your old carrier will usually convert the old SIM to a prepaid SIM. You can then add a second SIM to your device from a new carrier.

While porting your number is relatively easy, this also depends on how efficiently your carrier handles customer service. Some people don’t want to go through the transition period involved in porting a number.

With a dual SIM device, you can still receive calls and texts to your old SIM, and don’t have to worry about porting your number.

Stay Connected During Carrier Outages

Another lesser-known benefit of dual SIM phones is the ability to stay connected during carrier outages or coverage gaps. Carrier coverage can differ in certain areas, with some having better connectivity in certain zones. With a dual SIM phone, you can try to switch to your other SIM to see if you get better connectivity.

This also works when it comes to carrier-specific outages. If one carrier is experiencing technical difficulties, you can switch to your other SIM in the meantime.

Dual SIM Phones: Which Brands Make Them?

smartphone variety comparison

Dual SIM smartphones are more prevalent than ever, so they are no longer really limited to specific devices or brands. Most devices released since 2018 have dual SIM support.

However, smartphone companies with major stakes in China and developing markets tend to include dual SIM functionality more often. Their track record of dual SIM support is also longer, meaning that many devices released before 2018 from these brands will still have dual SIM slots.

Nevertheless, major American brands such as Apple and Google now also include dual SIM functionality in the newer iPhone and Pixel devices.

Other brands that frequently make dual SIM smartphones include Samsung, Huawei, Xiaomi, Sony, LG, and OnePlus. If you are interested in a dual SIM smartphone, check the specifications of a smartphone you are considering buying. This will let you know whether it supports dual SIM functionality.

How to Manage Your SIM Card

If you’re still hesitant about the technicalities of dual SIM phones, or want to find out more about your single SIM cards, there are tools to help you.

Managing your SIM cards isn’t as daunting as it seems. In fact, SIM cards actually have quite a bit of data and useful information you can use.

If you want to find out more about your own SIM, check out our guide on Android apps to manage your SIM cards 7 Useful Apps to Manage Your SIM Card on Android You probably don't think much about the SIM card on your Android phone. These apps let you manage your SIM and do more with it. Read More .

Related topics: Dual SIM Phones, eSIM, Mobile Accessory, Sim Card.

Affiliate Disclosure: By buying the products we recommend, you help keep the site alive. Read more.

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  1. Patty
    August 4, 2020 at 10:35 pm

    My brother in law bought a duel sim card phone on line looks like a 5 dollar phone lol but can he use 1 sim card I'm not even sure it came with one.. because he said it needs 2 Sims card. He can't even use a dollar store phone.

  2. Steven F
    November 26, 2019 at 1:06 pm

    Samsung's viral assistant?!?!?!


    Bixby is ot viral at all this guy is sponsored

  3. .
    January 9, 2018 at 6:50 am

    I owned a few dual SIM phones since 2014. Here's my few reason:
    1. Can be use 2 countries in 1 phone. Because I always visit to Thailand. No need to swap SIM each time I go to Thailand from Malaysia. single SIM smartphone have problem and sometimes I'll lost the SIM card.

  4. angela
    January 4, 2018 at 1:36 pm

    Will I be able to tell which number someone is calling me on? So whether it is my work number or my private number they are trying to reach me on?

  5. Kathy Harden
    April 21, 2017 at 10:07 pm

    I have a phone that take 2 Sims need to know what phone company is it compatible to to have it turned on

    • norma randle
      November 1, 2017 at 6:47 pm


  6. Tia GunZ
    January 22, 2017 at 9:45 pm

    I just found out about dual sim phones and I am quite excited. This opens a new chapter in my life for travel and adventure!!!

  7. Louise
    November 4, 2016 at 2:56 pm

    I bought a 10 inch Tablet Octa Core 2560X1600 IPS Bluetooth RAM 4GB ROM 64GB 8.0MP 3G MTK6592 Dual sim card Phone Call Tablets PC Android 5.1 Lollipop GPS electronics 9 10.1 White
    It says the Dual Sim card is not included I have no idea where to buy it and what it is used for . Can you explain all that to me and let me know where I can order the sim card if neccessary

  8. Pat O'Brien
    August 3, 2016 at 8:58 pm

    I'm looking into a dual sim phone to use in two different countries(Canada and the US) I want to avoid roaming charges. Will this work?

    Pat O

    • Tim
      October 23, 2016 at 6:29 pm

      Many mobile carriers have roaming between our two countries with no charges or roaming fees. Companies like Sprint just have you turn on a feature called "one world" and that allows you to travel to in the US Canada and Mexico without paying any roaming fees though you may have limited data (only 3g) in some areas like Mexico. If your provider does not allow this option the way Sprint does it would be a good idea to get a second Sim local to whatever region you choose away from home. I would strongly suggest a prepaid plan has most cell phone plans are Laden with taxes and fees and it doesn't make sense

  9. G B
    December 11, 2015 at 6:30 pm

    I am wondering whether or not to go for the Lumia 535 (single sim) or Lumia 540 (dual sim). I know there are other differences, but on this alone, what should I buy?


  10. Martin
    April 12, 2015 at 9:08 am

    My dear people... please, I recommend you to buy single sim phones. Because, whatever the features does dual sim have, the high electromagnetic can't be ignored in dual sim mobiles (even the high models too). So, I beg you. Even it make you uncomfortable, please buy single sim. It's safe side. Due to high radiation of dual sim mobiles, cause brain tumours, memory impairment, etc., Contact me through mail for furthur issues. Please take concern my comment. Thank you.

    • Robert
      May 21, 2015 at 12:28 pm

      Very clear and very right explanation.
      Avoid dual sim phones!
      It has twice as much SAR level (specific absorption rate).
      SAR electromagnetic radio waves lead to cancer and etc.

  11. Sue Hill
    March 28, 2015 at 2:30 pm

    I have two mobiles. One is on contract with talk mobile the other is with Vodafone pay as you go can I put both sims into a dual sim phone?

  12. David soloman
    March 6, 2015 at 4:41 pm

    Sure a dual sim set of phones for VIP ever lost your phone or power supply I want two single number phones for back up not going to use them at the same time bone heads AT&T x verizon,2nd account unnessasary costly these companies will be left in the ash heap of time just parasites,monopolies!!

  13. Timothy Liem
    October 3, 2012 at 3:26 pm

    LOL.. We in Indonesia already stuffed with local-branded-made-in-China dual-SIM phones since six years ago..

    • Rajaa Chowdhury
      October 5, 2012 at 7:37 am

      India is the biggest market for Dual SIM Handsets in the world. Popular since it's inception. :P Both branded and chinese stuff. :)

  14. Loreson San Juan
    October 3, 2012 at 3:07 pm

    dual sim phones are booming in the Philippines

    • Rajaa Chowdhury
      October 5, 2012 at 7:37 am

      India is the biggest market for Dual SIM Handsets in the world. Popular since it's inception. :P

  15. Eero
    October 3, 2012 at 12:18 pm

    In western countries it seems that dual SIMs are extremely rare and you can find only few models (operators do not really like it which is easy to understand). However, I think lot of people would like to have dual SIMs f.ex. for identity management (business / private), traveling etc which were pretty well captured in the article. One additional aspect is that in some areas the coverage can be be poor when using only one SIM.

    There are also different types of dual SIM. Dual Sim Stand-by (DSS) - allows the device to switch from one network to the other when required and Dual Sim Active (DSA) - allows the device to be connected to both networks at the same time. The device can switch between two calls without dropping either. DSS based devices are in overwhelming majority, only few models claim they are dual SIM active.

  16. Reý Aetar
    October 2, 2012 at 12:01 pm

    good but except those branded ones all chenese phones have a dual sim
    some even have 3 sims

  17. Rob Hindle
    October 2, 2012 at 10:43 am

    Slightly off topic but related question:

    Can I get dual phone SIMs? What I mean is two sims programmed to the same number.

    The reason I ask is that I have 2 phones. One is an Android with the problems of smart-phones - not very robust, short battery life etc.

    The other is a conventional inexpensive "basic" model - I use that in higher risk situations like outdoor activities where it could get damaged, wet, lost or for travel when the long standby and quite good in normal use battery life are an advantage, also if you're not careful smart phones can rack up enormous roaming charges when travelling.

    It would be useful to have both on the same phone number.

    • Laga Mahesa
      October 2, 2012 at 12:01 pm

      Technically feasible, but extremely problematic in practice. If you have them both turned on, they'll cancel each other out and dramatically consume your battery because they're fighting both each other and the cell towers. The problems incurred by this on the cell towers is why your cell provider won't give you a dupe - you'd have to make one yourself.

      Good luck with that!

    • Reý Aetar
      October 2, 2012 at 12:03 pm

      no u cant ,to get that you need to be a vip
      or u need permission from regional officer and a long process is there
      i saw one topic like that in yahoo answers long ago, unfortunately i cant get it now

    • Harish Jonnalagadda
      October 3, 2012 at 11:48 am

      Dont think that can be done, have tried to see if it can be a while ago.

  18. Rob Hindle
    October 2, 2012 at 10:34 am

    One alternative to dual sim is to simply swap the sim. The reason that's a pain is that, especially with smart phones, there will be settings to change each time. Some phones even need time and date resetting (why can't they just get that off the network?)

    • Laga Mahesa
      October 2, 2012 at 12:03 pm

      Symbian, right? Whichever, there is usually a special code you can 'call' to request carrier settings for your particular model. For example, with my provider I can text "gprs nokia 6600" to 3000 and it will reply with a carrier settings file, upon receipt of which my phone will prompt me to install it.

      Just save that as a contact and you're gold.

  19. Rob Hindle
    October 2, 2012 at 10:30 am

    Dual SIM can be useful in mountainous areas (in UK: Scotland, Snowdonia, Lake District, Peak District) with patchy network coverage, if you don't get a signal with one provider you might with another.

    Another aspect of that which used to be covered in mobile phone reviews, but no more, is how good the phone is with weak signals.

  20. Dimal Chandrasiri
    October 2, 2012 at 9:28 am

    So I heard that dual sim phones use twice the signals as a single sim phone. will this affect to human health since lot of teenagers use them where I live.

    • Laga Mahesa
      October 2, 2012 at 12:04 pm

      Don't worry about it. If you're living in a city, even a small one, there are worse concerns you need to deal with first.

  21. VS Vishnu
    October 2, 2012 at 9:13 am


  22. Reynldo Mallorca
    October 2, 2012 at 8:37 am


  23. Ahmed Khalil
    October 2, 2012 at 7:46 am

    it has big side effect too, that its power radiation is more than the normal one so it is more harm than the normal

  24. Tony
    October 2, 2012 at 7:06 am

    Hi! Speaking about dual or duo sim phones is nothing, I found here in India a Triple or Trio SIM phone, not a name brand but surely works, it is ideal for those with Wife, Work and With Other on the Side, jejeje, just kidding there but yes there is a Triple or Trio SIM phone in India, look for it on Google.

    • Harish Jonnalagadda
      October 3, 2012 at 11:47 am

      Yeah I know I saw the ads on the telly too! Why would anyone need so many cards is beyond me.

  25. Anonymous
    October 2, 2012 at 1:40 am

    Dual SIM can be a real boon for the ex-pat or overseas businessman, it is a shame the real top smartphones don't have the facility.

    • Laga Mahesa
      October 2, 2012 at 12:21 pm

      The higher you get up the smartphone ladder, the less likely you'll see dual-sim support. The carriers won't have it, and carriers are where the bulk of the profits come in as they subsidize for their victi...users.

  26. Mark Silos
    October 1, 2012 at 11:55 pm

    Here in the philippines dual sim is use to cut cost in calling and texting other network providers. and due to network competition they give different promo's specially on pre-paids. Some areas don't have signals in which other network may have. You can buy pre-paid sim anytime you want in any network as much as P10.00 or around $0.23 cents.

    • Yaara Lancet
      October 2, 2012 at 3:59 pm

      That's pretty cool. Thanks for sharing!

  27. Oliver Rainer
    October 1, 2012 at 10:22 pm

    Dual sim reminds me of my old Nokia case.

  28. Scott MacDonald
    October 1, 2012 at 8:57 pm

    If they were affordable enough, I'd love a pay as you go dual simmer.

    • André Kamara
      October 1, 2012 at 9:28 pm

      Check the new Acer Gallant Duos. It's €180, €150 without VAT and you have a RAM of 1Gb with Android Ice Cream Sandwich. I think Huawei also made some affordable ones.

      • Hatem Sindi
        October 1, 2012 at 9:34 pm

        Does it work with wind canada and t-mobile usa

        • André Kamara
          October 1, 2012 at 9:37 pm

          I'm not sure as I don't live in America, but there's no reason why it shouldn't.

      • Yaara Lancet
        October 2, 2012 at 3:57 pm

        Thanks for the recommendation Andre!

        • Anonymous
          October 2, 2012 at 5:56 pm

          You're welcome :-)

    • Rajaa Chowdhury
      October 2, 2012 at 8:00 am

      Checkout the Samsung Galaxy Duos Lite GT-S5302. Android smartphone with dual SIM which has been launched a month back and cost around US $120 in India.

    • Rajaa Chowdhury
      October 2, 2012 at 8:01 am

      Samsung Galaxy Y Duos Lite GT-S5302

      • Anonymous
        October 2, 2012 at 5:55 pm

        I was about to buy this one last month, but the RAM is not big enough and it has an "old" version on Android.

        • Rajaa Chowdhury
          October 3, 2012 at 12:26 am


          It is 4GB internal and the Android is 4.0.4 Icecream Sandwich.

        • Rajaa Chowdhury
          October 3, 2012 at 12:31 am

          Oh am sorry, I mixed it up with the one I am using which is a Samsung alaxy Chat GT-B5330 but it is a single SIM smartphone. Kindly ignore my previous comment Andre. Sorry for the mistake. Samsung Galaxy Y Duos Lite GT-S5302 runs on Androind GingerBread 2.3.6 and User Memory 2GB for multimedia and 1GB for applications and External Memory is upto 32GB.

    • Rajaa Chowdhury
      October 2, 2012 at 8:06 am

      Dual SIM phones became popular in my country India initially solely because of the affordability factor. Being a developing country, where the standard of living is generally not at par with developed nations, people seldom could spent on two handsets. therefore, the initial dual SIM handset offerings were very basic in nature. However, with passing time, the advantage of a dual SIM handset drove through to the market, and more and more people started accepting it. As the acceptance grew, varied became the models, brands, features and offerings. Now dual SIM smartphones are very common sight in India.

      • Yaara Lancet
        October 2, 2012 at 3:59 pm

        Thanks for the device recommendations and your comment. It's surprising how little we see of these devices in the west, I know so many people who carry around two devices.

    • Rajaa Chowdhury
      October 3, 2012 at 9:04 pm

      Another very recent awesome dual smartpone mobile is the Sony Xperia Tipo Dual. It costs around US $180 in India. The specs are pretty decent and yes it comes with Android ICS. :) More details at