All our phones are dual sim (often referred to as dual IMEI). This usually means (but not always), that your new phone is capable of receiving 4G or 3G signal in sim 1, and 3G or 2G service in sim 2 at the same time – or vice versa, because you can choose which sim card to use as your primary card for data.
Whichever card you nominate for mobile or cellular data, that will be your 4G card.
Rather than having two sims running at full power all the time, your phone saves energy by making you nominate just one sim for data use. That leaves the secondary sim on standby, coming to life only for incoming calls or texts, or outgoing calls or texts if you choose to route them through that second sim.
This means that you can run your main phone account in one sim (work), and a home or private number in slot two. When travelling overseas this is particularly useful because you can keep your primary NZ number in slot one so friends can ring or text you, but buy a cheap local prepaid sim in your destination country and switch to that as your primary 4G/data provider. This could save you a fortune in roaming fees.
Dual sim is not always functional
There are times when dual sim won’t always be available on your phone. Traditionally dual sim phones have provided 4G/3G in one slot and only 2G GSM in the standby slot. All well and good, but networks around the world have begun turning off their 2G networks. Even if your second sim card supported 3G, it suddenly didn’t work in a 2G-only slot.
In NZ, Spark never had 2G, and 2Degrees switched off its 2G service in March 2018. Only Vodafone and its affiliate networks still offer 2G. So as long as your secondary sim is Vodafone, you can still have a dual sim phone.
Most of the phones we sell at the Outdoor Phone Store have 4G/3G on both sim slots, rather than a 4G and 2G configuration, but a notable exception is the AGM M-series which is a 4G/2G.
Spark/Skinny sims MUST go in sim 1 for most of our phones, because Spark has no 2G. Now 2Degrees has done the same. A Spark/2Deg dual sim combination will no longer always work because both need sim 1, but a Spark/Voda or 2Deg/Voda will provide full functionality.
You might be lucky – some new phones will allow full functionality on a Spark/2Deg combo. But some won’t. An example? The VK S8 with a Spark/2Deg combo shows 4G/3G functionality. The Active Rugged shows 3G/3G in the same situation, but if you go Spark/Voda it shows 4G/3G.
What about phones that only work on Vodafone/2Degrees?
To get dual sim functionality you must load 2Degrees in sim slot 1 if also running Vodafone. The phone will be fully functional on either network as a single sim phone.
Why does my phone drop back to 3G even though I know the nearest cellsite is 4G?
4G signals become unstable more than a couple of km from the cellsite, and phones will automatically drop down to 3G once you exceed the 4G signal perimeter.