You’ve likely seen the term “dual-SIM” before, but you may find yourself wondering what that means or why such a thing would exist.

Stateside, dual-SIM phones are practically unheard of, mainly due to the subsidy structure our mobile industry is based on. But in smaller, emerging markets, dual-SIM phones have been around for years. Globally, such phones are growing in popularity. Devices like the Galaxy S Duos 2, Galaxy Note 3 Neo Duos, or even a modified HTC One with a removable back come with two SIM slots.

Some manufacturers, such as LG and Samsung, are even taking multi-SIM phones to the next level with triple-SIM handsets. Back in February, Samsung and LG announced two new handsets, the Galaxy Star Trios and Optimus L1 II Tri, respectively.

Why do people need more than one SIM in any particular smartphone? Why on earth would someone need three or more SIMs? The answer is more simple than you might think.

 

Travel

travel

One of the most obvious reasons multi-SIM devices exist is for international travel.

Roaming charges can run up the bill excruciatingly fast and sometimes a local SIM is the only logical way to stay connected while traveling. However, if you pop a new SIM into your phone, you become unavailable to all those people back home who have your number.

Using a dual-SIM setup, you can use both a temporary, local SIM for data and local calls while keeping your personal SIM from home in your phone for family emergencies, work, or other uses.

In more recent years, things like instant messaging, VoIP, and various other forms of communication have nullified some of these use cases, but it’s still a viable option for traveling abroad and keeping expensive roaming charges to a minimum.

 

Big savings

Dual-SIM HTC One

In emerging markets, prepaid plans are commonplace and postpaid service is often overpriced.

Back on Episode 088 of the Pocketnow Weekly, we had a listener mail in with a question concerning multi-SIM phones and how many people used up to 10-SIM expansions. Our own Jaime Rivera weighed in, explaining that he, too, lives in an emerging market. He said he used to pay over $140 per month for his cell service. The data speeds and calling was ideal, but the pricing was hard to swallow.

Various prepaid plans come with different offers, however. Some offer better data pricing, yet come with horrible calling plans. Another prepaid service may offer better calling options, but poor data services and pricing.

By switching to two separate prepaid plans, Jaime was able to get the best of both worlds without breaking the bank. He said after the switch, his monthly wireless costs dropped to just $50. On one prepaid carrier, he can get HSPA+ data and “a ton of minutes”, while on the other carrier, the data is horrible, but he can call the U.S. for no additional charge.

This is one of the most popular uses for dual-SIM phones. Using SIM adapters, which often squeeze beneath the battery door, some people are able to add even more SIMs to their phone and juggle even more prepaid deals.

 

Juggling service

two-phones

Service, especially in emerging markets, can often be an issue, though.

Even here in the States where we (fortunately) have some great options for service, I carry two devices daily to try and avoid simply going without data in certain areas. For instance, I use T-Mobile as my primary service provider, simply because it offers truly unlimited data. However, T-Mobile’s service – particularly in rural areas – can get very spotty. Driving outside Charlotte results in dropping to EDGE for no less than an hour drive in any direction. That’s exactly why I also carry a Verizon phone every day, for that exact situation.

However, not everyone likes to carry more than one phone. With a dual-SIM phone, you can achieve the same effect with a single device, thus freeing your other hand or pocket from an additional phone.

 

Two numbers, one phone

speakerphone

In that very same vein, sometimes companies will equip their employees with a work device. In BYOD (bring your own device) situations, instead of carrying two phones all the time, you could simply insert your work SIM into a dual-SIM phone while maintaining the work and personal separation you need.

Of course, this can be simulated using a service like Google Voice, but it’s good to know this is still an option.

 

XperiaE

Dual-SIM devices won’t appeal to everyone, but they certainly have a place in this world. The more expensive postpaid carriers become, the more frugal wireless consumers will look to prepaid options and the more practical dual-SIM smartphones will be.

That said, most multi-SIM phones are geared towards emerging markets, meaning very few are like the high-end flagships many have grown used to. The Galaxy Note 3 Neo Duos, for example, is one of the most high-end dual-SIM phones around, with a 720p Super AMOLED display and a Snapdragon 400 SoC.

Here’s to hoping more high-end multi-SIM phone options will begin to emerge as the not-so-new technology grows in popularity around the globe.