ZenFone 2

One of the coolest features of the new ASUS ZenFone 2 is that it's one of the first "mainstream" devices to come with dual SIM card slots. Hold on — that doesn't mean you're going to be doubling down on network speeds or anything, as we explained here, but it does bring two physical phone lines into one device.

This isn't anything new, of course. Dual-SIM phones have been around a long time, and plenty of people use them outside of North America for various reasons. In some places, dual-SIM phones are the norm to prevent roaming fees or to ensure you have coverage everywhere you will be going. But in North America, where carriers have traditionally dictated the market (and they would never want you to be able to use a different network's SIM in their phone easily), it's just something we rarely see.

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That's why we want to take a few minutes and show how easy it is to use two SIM cards on the ASUS ZenFone 2.

SIM card trays

The first thing to do is decide why you want two SIM cards, or if you want to use two at all. The ZenFone 2 does not have a high-speed data connection on the second SIM card. That means you only have service for calls, text messaging, and a 2G data connection on SIM 2.

SIM 1 supports a fast LTE connection from both AT&T and T-Mobile in the U.S., as well as all Canadian GSM carriers. It also supports AWS bands, so you'll be able to use T-Mobile (U.S.) and Wind, Mobilicity and Videotron (Canada) for HSPA+ data.

  • GSM voice and EDGE data (2G): 850 MHz, 900 MHz, 1800 MHz, 1900 MHz
  • UMTS/HSPA data (3G): 850 MHz, 900 MHz, 1700 MHz, 1900 MHz, 2100 MHz
  • LTE: Band 1, Band 2, Band 3, Band 4, Band 5, Band 7, Band 8, Band 17, Band 20

More: What radio bands do I need on my unlocked phone?

You can mix and match any supported network SIM card freely — the phone is completely unlocked — but you'll only be using SIM one for a data connection.

You insert the SIM cards just like you would on any other phone. Slide them into the trays under the back cover. The only difference is that there are two of them.

Once you have two SIM cards in place (the ZenFone 2 is pretty good about filling in network information automatically) you're ready to accept and initiate calls and messages using two phone numbers.

Using the software dialer and messaging app that comes with the ZenFone 2, this is super simple. It might not work as well (or at all) with third party dialers and messaging apps from Google Play, so you might not be able to use your favorite apps. The ASUS apps work well, though, and it's not a terrible experience.

Receiving calls and messages requires you to do nothing. They come in, as normal, using whatever number the person calling or texting you used to call or text you. This makes your incoming call log a little messy, but there are filtering options (tap the little SIM card icon at the top of the list) to see which SIM the calls came in on. When you receive a message, the chat bubble will have an indicator of which SIM card received it, so you know which number to use when your respond.

Making calls and sending texts is almost as easy. To make a call, bring up the dialer, enter the number you want to call or use the address book to pick a name, then press the button on the bottom for SIM one or SIM two.

To send a text, enter who you want to send it to, type out what you want to say, then choose which SIM to use to send it from the icons in the text entry field.

That's about it! While this setup isn't perfect for people who want two high-speed data networks on demand (you need to swap SIM cards for that) it's great for anyone who needs two lines on one phone. You'll have two separate voicemail boxes, two separate call logs, and two separate bills — perfect for those expense reports.

The ZenFone 2 is turning out to be one of the great phones of 2015, and we're not even close to finished. Taking control of who you pay each month for cell service has never been easier now that we have awesome unlocked phones like the ZenFone 2.

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