Global dual-SIM smartphone sales will grow 19% from 431 million units in 2015 to 514 million in 2016. Almost one in three of the 1.6 billion smartphones sold globally in 2016 will be dual-SIM models, according to data compiled by Strategy Analytics.

China and India are by far the two largest country markets for dual-SIM smartphones worldwide. Dual-SIM smartphones are popular in China and India because they allow consumers to select the cheapest tariff rates for voice or data plans, as well as access better cellular coverage without roaming charges, said Linda Sui, director at Strategy Analytics.

Leading smartphone vendors, such as Samsung Electronics, Lenovo and Micromax, are focusing on marketing their dual-SIM Android models in China and India. Meanwhile, Apple is missing out on a huge half-billion-unit global market for not offering a dual-SIM iPhone, said the research firm.