17x were introduced. In 2017, 16x and 19x were introduced. In December 2016, each cell phone number was required to be consigned to a real name in mainland China. In November 2010, MIIT has started the trial mobile number portability service in Tianjin and Hainan, in 2012 the trial has extended to Jiangxi, Hubei and Yunan provinces. In 10 November 2019, all provinces started accepting MNP requests for all mobile providers, except for technical difficults, the MVNO phones, satellite phones and IoT phones. Mobile service providers can be identified by the first three or four digits as follows: 1 – China Unicom before 2009 2 – Operated by China Transport Telecommunication Information Group Co., Ltd. 3 – TD-SCDMA networks are being deprecated by China Mobile since c.2020 4 – GSM networks are being deprecated by China Unicom since c.2020 5 – CDMA2000 networks are being deprecated by China Telecom since c.2020 Calling formats To call phone numbers in China one of the following formats is used: For fixed phones: xxx xxxx | xxxx xxxx Calls within the same area code 0yyy xxx xxxx | 0yyy xxxx xxxx Calls from other areas within China +86 yyy xxx xxxx | +86 yyy xxxx xxxx Calls from outside China For mobile phones: 1nn xxxx xxxx Calls to mobile phones within China +86 1nn xxxx xxxx Calls to mobiles from outside China Area 1 – Capital Operation Center The prefix one is used exclusively by the national capital, Beijing Municipality. Beijing – 10 (formerly 1, abolished after GSM was introduced, to avoid conflict with mobile phone numbers with prefix 0 added (e.g. 0139-xxxx-xxxx)) Area 2 – Country Communication System Operating Center These are area codes for the municipalities of Shanghai, Tianjin, and Chongqing, as well as several major cities with early access to telephones. These cities have upgraded to an 8-number system in the past decade. All telephone numbers are 8-digit in these areas. Guangzhou – 20 Shanghai – 21 Tianjin – 22 Chongqing – 23 3 Shenyang, Tieling, Fushun, Benxi – 24 4 Nanjing – 25 Wuhan, Huarong District of Ezhou – 27 Chengdu, Meishan, Ziyang – 28 5 Xi'an, Xianyang – 29 6 3 - Formerly 811, 814, 819, 810, abolished 1997. 4 - Formerly 410, 413, abolished 2011, and 414, abolished in 2014. 5 - Formerly 832, 833, abolished 2010. 6 - Formerly 910, abolished 2006. It's still unclear whether 26