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
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.