A Beginner’s Guide to Dual-SIM Phones

Mobile technology has come a long way since the brick phones of the 1980s. These days it is integrated so closely into our lives you may not even know it is there. Interestingly, this is also the case with dual-SIM smartphones.

Dual-SIM has been around since 2000 when Benefon (now Twig Com Ltd.) released the Benefon Twin, the world’s first dual-SIM phone. Major players like Nokia, Samsung, and Sony followed suit about a decade later in the early 2010s, while Apple released its first dual-SIM phones (the iPhone XS models) in 2018. However, despite being around for a while, many mobile users do not realise their phone has the functionality and aren’t even sure what a dual-SIM phone is and what it can do.

That is why we have written this explainer guide – to help mobile users understand what dual-SIM is so you can decide if it could be of benefit to you.

What is Dual-SIM?

A dual-SIM phone is exactly what it sounds like: a phone with dual (i.e. two) SIM cards.

Any phone requires a SIM card to connect to a mobile network and usually has a tray that this card is slotted into. A phone that can hold two SIM cards is called a dual-SIM phone. This could be two standard SIM cards or a standard SIM card and an embedded SIM (eSIM).

Each SIM card has its own phone number and network connection. This means you can make or receive phone calls, send or receive text messages, or connect to the internet on each SIM card simultaneously while keeping them entirely separate.

However, while the concept is the same – one phone, two SIM cards – not all dual-SIM phones work the same way. There are different types of dual-SIM modes.

What are the Different Types of Dual-SIM Modes?

The original method for using two SIM cards in the same phone was via a dual-SIM adaptor – a somewhat cumbersome tool that did the job but took some time to set up. Fortunately, dual-SIM functionality has been given a lot of attention and evolved since then.

These are the 3 different dual-SIM modes:

  • Dual SIM Single Standby (Passive) – A dual-SIM passive phone can use two different SIM cards but only one can be active at any time. This means that you can use the one SIM card to make a call but while you are doing so the other SIM card will be inactive and unreachable. This mode is only available in older phones, not smartphones.
  • Dual SIM Dual Standby – A dual-SIM dual-standby phone is a hybrid between dual-SIM dual-active and dual-SIM single standby. This means both SIM cards will be active but in standby mode until you start using one of them, in which case the other will become inactive. Most dual-SIM smartphones currently on the market are dual-SIM dual-standby.
  • Dual SIM Dual Active – A dual-SIM dual-active phone can use both SIM cards at the same time. This means both SIM cards are permanently active, so you can use the one and the other will still be able to receive phone calls or text messages. If you are on a call on the one and get another call on the other, you will get notified and be able to switch.

Can Dual-SIM Phones be on Different Networks?

Technically, yes, but some phones are locked to a specific network provider.

SIM only phones or phones bought directly from the manufacturer are generally not locked, but a phone bought on a contract from a carrier will usually be locked to the provider the contract is with. This is to prevent users from using those phones with competing carriers.

It is, however, possible to unlock a phone that has been locked to a specific carrier. This usually involves contacting the carrier and requesting that they unlock the phone.

What are the Advantages of Dual-SIM?

Although dual-SIM phones tend to be more popular amongst business people, they offer several advantages that even everyday mobile users will appreciate and benefit from.

  • Two phone numbers – The biggest advantage of using a dual-SIM phone is, unsurprisingly, having two phone numbers. This is particularly useful if you want to keep your work and personal line separate but don’t want to carry around two phones.
  • Cheaper international tariffs – If you travel often and don’t want to spend exorbitant amounts on international roaming charges, having a dual-SIM phone means you can keep your primary number and use the second slot for a local SIM card.
  • Mix and match data plans – One of the biggest drawcards of using a dual-SIM phone is being able to combine different plans. You could have a great voice plan on one SIM card and a cost-effective data plan on the other for greater savings.
  • More network coverage – Being able to use two different plans also means greater network coverage. If you travel to a particular area frequently but your existing provider doesn’t offer good coverage in that area, you can simply get a plan from a provider that does.

How Do I Set up Dual-SIM?

There are different ways you can get dual SIM functionality on your phone depending on what phone you have and where you are in the world. Some phones use two nano-SIM cards while others use a nano-SIM card and eSIM.

The next part of this guide walks you through setting up dual-SIM functionality on iPhone and Android devices. iPhones use an eSIM and nano-SIM card combination while Android phones may use the nano-SIM card/eSIM combination or two nano-SIM cards.

Note: This process may vary depending on the phone and carrier you use. For this guide, we are using an eSIM from eSIM.net for the SIM card/eSIM combination on iPhone.

How to Set up Dual-SIM on iPhone

Scan a QR code 

  1. Open the Camera app and scan your QR code
  2. Tap the Cellular Plan Detected notification when it appears
  3. Tap Continue at the bottom of the screen
  4. Select Add Cellular Plan.

Other ways to set up a dual-SIM iPhone include through a carrier app, by entering the information manually or installing an assigned cellular plan provided by a carrier.

You can find a more in-depth guide for these different options here.

How to Set up Dual-SIM on Android

The process for setting up dual-SIM functionality on Android phones is quite similar so this should be a good guideline whether you’re using a Samsung, Motorola, or OnePlus device. For this guide, we are setting it up on a Google Pixel device.

Add an eSIM as a second SIM

  1. Go into your phone’s Settings
  2. Tap Network & internet
  3. Select Add next to Mobile Network
  4. Tap “Download a SIM instead?”
  5. Select Yes when asked, “Use 2 SIMs?” and let your phone update
  6. Go to Settings again after your phone updates
  7. Tap on Network & Internet and then Mobile network
  8. Go into your networks to set call and text preferences

Add a SIM card as a second SIM

  1. Insert the SIM card
  2. Select Yes when asked, “Use 2 SIMs?” and let your phone update
  3. Go to Settings again after your phone updates
  4. Tap on Network & Internet and then Mobile network
  5. Go into your networks to set call and text preferences

If you want to watch a really good video overview from our peers over at TechAdvisor, check it out here.

About Aislinn Corbet

Occasional writer and full time Android enthusiast

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