One of the device properties detected by DeviceAtlas is whether a device can support multiple SIM cards, which allows us to look specifically at dual SIM devices. We looked into web traffic statistics to learn in which regions multiple SIM cards are the most popular.

Two decades of dual SIM phones

The SIM card is a tiny addition to GSM mobile phones that allows them to connect to a mobile network. Its initial purpose was to ensure that a subscriber could maintain their identity on the network regardless of the device. In other words, SIM cards help us keep our phone numbers when we change devices. You can learn a lot about SIM cards from an excellent article by DeviceAtlas CTO Ronan Cremin including, for example, that SIMs can support TCP/IP and run a web server.

Available since around the year 2000, dual SIM phones were aimed at addressing the growing need to be able to use two different phone numbers in one device. Perhaps the most important reason was varying rates for calls, texts, and mobile data. A lot of MNOs offered cheaper or even free calls and texts within their own network while calling or texting a competitor’s network could be a lot more expensive.

Other use cases included expats and other travelers who used dual SIM phones to be able to use SIM cards from two countries to avoid roaming charges. Also, some users preferred to keep business and personal SIM cards on the same phone rather than carry two devices.

All these factors make dual SIM phones desirable enough to be available in almost every corner of the globe.

Phones can handle SIMs in many ways

There are a few ways in which phones handle more than one SIM card. Some dual SIM phones are effectively single SIM only allowing the user to switch between SIM cards. There are also dual standby phones which have only one active channel at a time—during a call the second channel is blocked. The most sophisticated dual SIM devices allow for two active SIM cards that can work simultaneously.

Dual SIM phones are particularly popular among Chinese manufacturers who often release new devices exclusively as dual SIM models—with no single SIM alternative. The following table shows some of the most recent dual-SIM-only phones available.

Interestingly, there are phones that support more than two SIM cards for even more demanding users. Here are some triple and quad SIM phones available.

Dual SIM phones are most used in India

To learn in which markets dual SIM phones are most used we looked into DeviceAtlas statistics for Q2 2017 focusing on the ‘number of SIM slots’ hardware property detectable through DeviceAtlas.

India is now the only country where dual SIM phones are more popular than single SIM phones at 68% of web traffic share. Other highly dual SIM-focused markets include Nigeria (49%), Brazil (43%) and Egypt (42%). Interestingly, countries, where dual SIM phones are the least popular, are developed markets including the USA, Canada, and Australia at around 3.5-4% of share.

Detect dual SIM phones with DeviceAtlas

Potential use cases for detecting dual SIM phones with DeviceAtlas include targeting ads to dual SIM phone users for MNO offers,, such as international call rates, data plans, cheap roaming offers, or phone upgrades. The number of SIM slots property also provides an excellent addition to web analytics solutions, both for internal and external users, that can be used for Business Intelligence and data-driven decisions related to sales and marketing.