Five Reasons To Consider Using Multiple SIMs

Five Reasons To Consider Using Multiple SIMs

Because the SIM card in your phone dictates the number people can contact you on, it might seem axiomatic that one should be enough for anyone. Yet there are circumstances where having more than one SIM makes sense. Here are five reasons to consider multiple SIMs.

SIM card picture from Shutterstock

1. To cut down on roaming bills

Although fees for international roaming have dropped slightly this year and carriers have to be more proactive in notifying you about what you’re spending, the costs involved remain ridiculously high. Our top recommendation for avoiding hideous bill shock is to use a separate SIM overseas. If you’re a regular traveller, a specific travel SIM can be useful; if it’s a one-off vacation, buy a prepaid SIM for the country you’re visiting.

2. To manage data costs in Australia

If you’re travelling regularly in Australia, then it can seem tempting to use tethering to access data on the road (presuming your carrier supports it; the major network players do, but it is sometimes blocked on prepaid plans). However, if your data allowance isn’t generous enough, that can be expensive. A better option is often to have a separate SIM for a dedicated Wi-Fi hotspot, or for use in a 3G-enabled tablet. If you choose the right prepaid plan, that can be cheaper and less hassle.

3. To improve battery life

Cost aside, one big disadvantage of running tethering is that it drains your battery faster than a bad case of Bali Belly drains your bowels. Tether for too long and you won’t be using your phone for anything. In that context, spreading the load across multiple devices can be helpful.

4. Because you don’t necessarily need multiple plans

Running multiple SIMs doesn’t necessarily mean managing multiple plans. Telstra now offers data sharing across multiple SIMs, and Optus is mulling a similar feature.

5. Because you don’t necessarily need multiple devices

Most of the examples we’ve discussed so far involve using multiple SIMs in separate devices, but there are also benefits to having multiple SIMs in the same phone. On the domestic front, that can allow you to separate work and personal calls without needing multiple devices; overseas, it eliminates fiddly SIM switching when you land. The most prominent device in this space right now is arguably Kogan’s $199 Agora phone.

When have you found multiple SIMs useful? Tell us in the comments.

Lifehacker Australia editor Angus Kidman has yet to meet a SIM he couldn’t deploy somehow. His Road Worrier column, looking at technology and organising tips for travellers, appears each week on Lifehacker.


  • I would Love a phone that could take two sims. One for me and one for work.

    Then, I’d like to be able to say, it’s the weekend or I’m on holiday, turn off the work sim and answer calls from that sim with this voice mail message.

  • If you’re in Europe then multiple SIMs are extremely useful. There are many border localities where you’re closer to the tower of another country than the one you’re physically in.

    And then there are places where you’re driving on major roads and can’t quite work out which country you’re in – particularly around northern part of western Europe.

  • I used to have two numbers, but a single SIM. One number for work, one for personal. Both numbers were active at the same time and I could dial out on either one and receive calls on both. Optus offer something similar called Dual SIM (not sure how long name will last given the profusion of dual SIM phones). They’re both supposedly aimed at corporate account customers, but when I had the service with Telstra it didn’t matter to them that I was just a personal customer.

    Clearly both accounts need to be with the same carrier. They also need to be post paid rather than pre-paid.

    The ability to do this has been part of the relevant standards for years, so it should be available across all mobile providers but tends not to be.

    If you’re interested in using this option then read up about it and take a print out of relevant information with you when you ask for it as few of the Telstra reps know about it.

    • Just out of curiosity, how do you select what number you’re dialling out from and sending messages from? Secondly, are you able to set up various “sections” of your phone – such as one SMS inbox for your personal number and another for the corporate number?

      Just wondering as it sounds like it would need to be embedded into the software on the phone, and I’m curious that if that’s what is needed, are only some phones supported? The only other way I can imagine it working is sending off a text message to your provider to “switch” the outgoing number which is useful but not as seamless as I’d like for it to be practical for my situation.

      • You just need to put something in front of the number being dialled. From memory (and it’s a while since I used this) it was an asterisk. I just set my address book to have the leading character(s) in front of the stored phone number. There’s no separate address book as the dual number aspect is a function of the SIM card rather than the phone. I don’t think I ever used SMS capabilities (I’m over 40, SMS is for young whipper-snappers 🙂 so can’t say much about that side of things.

  • Quite often the provider who offers the best deal on your calls and text will not offer the best deal on your data.
    Furthermore, there are many different promotional offers that apply only to one but not the other.

    That’s why it could be a good idea to have a dual-SIM phone where you can use one SIM for calls and text and the other for your data while on the go and also as a wifi hotspot for your other devices (e.g. laptop or tablet) when out and about.

    Our 100% free and comprehensive reports on mobile prepaid plans and broadband internet (including mobile broadband) will point you out to the BEST deals currently in the market, as identified by our own independent research. No email opt-in required!

  • 1) You would need dual sims when you have one sim specifically for work and another for private.
    2) Where the work sim is paid for by your employer, you don’t want he hassle of separating the private numbers from the call record/bills, every month. It would be waste of time and hassle.
    3) If you would like to have different ring or profile settings for work and private. If during work hours you anticipate low call volume from private and have hospital/EMs calls from family coming in, then you might want a ring or beep. But work can on silent mode. Or this can be applied vice versa.
    4) Where you don’t wish to reveal your private phone number to work colleagues

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