Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Disclosure Of Significant Investments In Subsidiaries [Abstract]

Detail Information of Subsidiaries

The detail information of the subsidiaries at the end of reporting period was as follows:

			Percentage of Ownership
			December 31
Name of Investor	Name of Investee	Main Businesses and Products	2018		2019		Note
Chunghwa Telecom Co., Ltd.	Senao International Co., Ltd. (“SENAO”)	Handset and peripherals retailer, sales of CHT mobile phone plans as an agent		28		28	a)
	Light Era Development Co., Ltd. (“LED”)	Planning and development of real estate and intelligent buildings, and property management		100		100
	Donghwa Telecom Co., Ltd. (“DHT”)	International private leased circuit, IP VPN service, and IP transit services		100		100
	Chunghwa Telecom Singapore Pte., Ltd. (“CHTS”)	International private leased circuit, IP VPN service, and IP transit services		100		100
	Chunghwa System Integration Co., Ltd. (“CHSI”)	Providing system integration services and telecommunications equipment		100		100
	Chunghwa Investment Co., Ltd. (“CHI”)	Investment		89		89
	CHIEF Telecom Inc. (“CHIEF”)	Network integration, internet data center (“IDC”), communications integration and cloud application services		57		57	b)
	CHYP Multimedia Marketing & Communications Co., Ltd. (“CHYP”)	Digital information supply services and advertisement services		100		100
	Prime Asia Investments Group Ltd. (B.V.I.) (“Prime Asia”)	Investment		100		100
	Spring House Entertainment Tech. Inc. (“SHE”)	Software design services, internet contents production and play, and motion picture production and distribution		56		56	c)
	Chunghwa Telecom Global, Inc. (“CHTG”)	International private leased circuit, internet services, and transit services		100		100
	Chunghwa Telecom Vietnam Co., Ltd. (“CHTV”)	Intelligent energy saving solutions, international circuit, and information and communication technology (“ICT”) services		100		100
	Smartfun Digital Co., Ltd. (“SFD”)	Providing diversified family education digital services		65		65
	Chunghwa Telecom Japan Co., Ltd. (“CHTJ”)	International private leased circuit, IP VPN service, and IP transit services		100		100
	Chunghwa Sochamp Technology Inc. (“CHST”)	Design, development and production of Automatic License Plate Recognition software and hardware		51		51
	Honghwa International Co., Ltd. (“HHI”)	Telecommunications engineering, sales agent of mobile phone plan application and other business services, etc.		100		100
	Chunghwa Leading Photonics Tech Co., Ltd. (“CLPT”)	Production and sale of electronic components and finished products		75		75
	Chunghwa Telecom (Thailand) Co., Ltd. (“CHTT”)	International private leased circuit, IP VPN service, ICT and cloud VAS services		100		100	d)

(Continued)

			Percentage of Ownership
			December 31
Name of Investor	Name of Investee	Main Businesses and Products	2018		2019		Note
	CHT Security Co., Ltd. (“CHTSC”)	Computing equipment installation, wholesale of computing and business machinery equipment and software, management consulting services, data processing services, digital information supply services and internet identify services		80		80
Senao International Co., Ltd.	Senao International (Samoa) Holding Ltd. (“SIS”)	International investment		100		100
	Youth Co., Ltd. (“Youth”)	Sale of information and communication technologies products		93		93	e)
	Aval Technologies Co., Ltd. (“Aval”)	Sale of information and communication technologies products		100		100
	Senyoung Insurance Agent Co., Ltd. (“SENYOUNG”)	Property and liability insurance agency		100		100
Youth Co., Ltd.	ISPOT Co., Ltd. (“ISPOT”)	Sale of information and communication technologies products		100		100
	Youyi Co., Ltd. (“Youyi”)	Maintenance of information and communication technologies products		100		100
Aval Technologies Co., Ltd. (“Aval”)	Wiin Technology Co., Ltd. (“Wiin”)	Sale of information and communication technologies products		—		100	f)
Senyoung Insurance Agent Co., Ltd.	Senaolife Insurance Agent Co., Ltd. (“Senaolife”)	Life insurance services		—		100	g)
Light Era Development Co., Ltd.	Taoyuan Asia Silicon Valley Innovation Co., Ltd. (“TASVI”)	Development of real estate		60		—	h)
CHIEF Telecom Inc.	Unigate Telecom Inc. (“Unigate”)	Telecommunications and internet service		100		100
	Chief International Corp. (“CIC”)	Telecommunications and internet service		100		100
	Shanghai Chief Telecom Co., Ltd. (“SCT”)	Telecommunications and internet service		49		49
Chunghwa System Integration Co., Ltd.	Concord Technology Co., Ltd. (“Concord”)	Investment		—		—	i)
Chunghwa Investment Co., Ltd.	Chunghwa Precision Test Tech. Co., Ltd. (“CHPT”)	Production and sale of semiconductor testing components and printed circuit board		34		34	j)
Chunghwa Precision Test Tech. Co., Ltd.	Chunghwa Precision Test Tech. USA Corporation (“CHPT (US)”)	Design and after-sale services of semiconductor testing components and printed circuit board		100		100
	CHPT Japan Co., Ltd. (“CHPT (JP)”)	Related services of electronic parts, machinery processed products and printed circuit board		100		100
	Chunghwa Precision Test Tech. International, Ltd. (“CHPT (International)”)	Wholesale and retail of electronic materials, and investment		100		100
Senao International (Samoa) Holding Ltd.	Senao International HK Limited (“SIHK”)	International investment		100		100

(Continued)

			Percentage of Ownership
			December 31
Name of Investor	Name of Investee	Main Businesses and Products	2018		2019		Note
Senao International HK Limited	Senao Trading (Fujian) Co., Ltd. (“STF”)	Sale of information and communication technologies products		100		—	k)
	Senao International Trading (Shanghai) Co., Ltd. (“SITS”)	Sale of information and communication technologies products		100		100
	Senao International Trading (Shanghai) Co., Ltd. (“SEITS”)	Maintenance of information and communication technologies products		—		—	l)
	Senao International Trading (Jiangsu) Co., Ltd. (“SITJ”)	Sale of information and communication technologies products		100		—	m)
Prime Asia Investments Group Ltd. (B.V.I.)	Chunghwa Hsingta Co., Ltd. (“CHC”)	Investment		100		100
Chunghwa Hsingta Co., Ltd. (“CHC”)	Chunghwa Telecom (China) Co., Ltd. (“CTC”)	Integrated information and communication solution services for enterprise clients, and intelligent energy network service		100		100
	Jiangsu Zhenhua Information Technology Company, LLC. (“JZIT”)	Providing intelligent energy saving solution and intelligent buildings services		—		—	n)
Chunghwa Precision Test Tech. International, Ltd.	Shanghai Taihua Electronic Technology Limited (“STET”)	Design of printed circuit board and related consultation service		100		100
	Su Zhou Precision Test Tech. Ltd. (“SZPT”)	Assembly processed of circuit board, design of printed circuit board and related consultation service		—		100	o)

(Concluded)

a) SENAO transferred its treasury stock to employees in June 2018 and the Company’s ownership interest in SENAO decreased to 28.18% as of December 31, 2018 and 2019.  As Chunghwa continues to control over half of the seats of the Board of Directors of SENAO (six out of eleven seats as of December 31, 2019) through the support of large beneficial stockholders, the accounts of SENAO are included in the consolidated financial statements.

b) CHIEF issued new shares in March and November 2018, and March and November 2019, as its employees exercised their options.  In addition, Chunghwa and CHI disposed some shares of CHIEF in May 2018 before CHIEF traded its shares on the General Stock Market of the Taipei Exchange according to the local requirements.  Furthermore, Chunghwa and CHI did not participate in the capital increase of CHIEF in June 2018.  Therefore, the Company’s ownership interest in CHIEF decreased to 60.23% and 59.75% as of December 31, 2018 and 2019, respectively.

c) SHE reduced 19.72% of its capital to offset accumulated deficits in December 2019 and the Company’s ownership interest in SHE remained the same.

d) The Company increased its investment in CHTT proportionally in October 2019 and the Company’s ownership interest in CHTT remained the same.

e) SENAO subscribed for all the shares in the capital increase of Youth in December 2018.  Therefore, the Company’s ownership interest in Youth increased from 89% to 93%.

f) Aval invested 100% equity shares of Wiin Technology Co., Ltd. (“Wiin”) in September 2019.

g) SENYOUNG invested 100% equity shares of Senaolife Insurance Agent Co., Ltd. (“Senaolife”) in November 2019.

h) LED invested 60% equity shares of Taoyuan Asia Silicon Valley Innovation Co., Ltd. (“TASVI”) in March 2018.  TASVI completed its liquidation in September 2019.

i) Concord completed its liquidation in January 2018.

j) CHI disposed some shares of CHPT from April to August 2018.  Therefore, its ownership interest in CHPT decreased to 34.25% as of December 31, 2018 and 2019.  However, considering the absolute and relative size of ownership interest, and the dispersion of shares owned by the other stockholders, the management concluded that the Company has a sufficiently dominant voting interest to direct the relevant activities; hence, CHPT is deemed as a subsidiary of the Company.

k) STF completed its liquidation in May 2019.

l) SEITS completed its liquidation in March 2018.

m) SITJ completed its liquidation in March 2019.

n) JZIT completed its liquidation in December 2018.

o) CHPT (International) invested 100% equity shares of Su Zhou Precision Test Tech. Ltd. (“SZPT”) in October 2019.