Dual SIM

When a second SIM card is installed, the phone may allow users to switch between two separate mobile network services manually, have hardware support for keeping both connections in a "standby" state for automatic switching, or have two transceivers to maintain both network connections at once.

Dual SIMs are popular for separating personal and business calls, in locations where lower prices apply to calls between clients of the same provider, where a single network may lack comprehensive coverage, and for travel across national and regional borders.

Some sub-contract Chinese companies supply inexpensive dual SIM handsets, mainly in Asian countries.

The phones, which also usually include touch screen interfaces and other modern features, typically retail for a much lower price than branded models.

While some such phones are sold under generic names or are rebadged by smaller companies under their own brand,[9] numerous manufacturers, especially in China, produce phones, including dual SIM models, under counterfeit trademarks such as those of Nokia or Samsung,[35] either as cosmetically-identical clones of the originals, or in completely different designs, with the logo of a notable manufacturer present in order to take advantage of brand recognition or brand image.

[8] Dual SIM phones are common in developing countries, especially in China, Southeast Asia and the Indian subcontinent, with local firms like Karbonn Mobiles, LYF, Micromax and Cherry Mobile releasing feature phones and smartphones incorporating multiple SIM slots.

[36][37] The French Wiko Mobile is also an example of rebadged Chinese Dual-SIM phones sold in few European countries as well as in North-West Africa.

Dual SIM phones allow separate numbers for personal and business calls on the same handset.