Revenue (Tables)

12 Months Ended

Dec. 31, 2019

Revenue [Abstract]

Summary of Revenue

Starting from 2018

	Year Ended December 31
	2018		2019
	NT$		NT$
	(In Millions)
Revenue from contracts with customers	$	214,461	$	206,360
Other revenues
Rental income		640		818
Other		382		342
		1,022		1,160
Total	$	215,483	$	207,520

Summary of Disaggregation of Revenue

a. Disaggregation of revenue

2018

	Domestic Fixed Communi- cations Business		Mobile Communi- cations Business		Internet Business		International Fixed Communi- cations Business		Others		Total
	NT$		NT$		NT$		NT$		NT$		NT$
	(In Millions)
Main Products and Service Revenues
Mobile services revenue	$	—	$	63,906	$	—	$	—	$	—	$	63,906
Sales of products		1,731		35,702		4		251		3,601		41,289
Local telephone and domestic long distance telephone    services revenue		29,996		—		—		—		—		29,996
Broadband access and domestic leased line services    revenue		22,453		—		—		—		—		22,453
Data Communications internet services revenue		—		—		21,137		—		—		21,137
International network and leased telephone services    revenue		—		—		—		8,724		—		8,724
Others		11,923		1,269		8,509		4,449		806		26,956
	$	66,103	$	100,877	$	29,650	$	13,424	$	4,407	$	214,461

2019

	Domestic Fixed Communi- cations Business		Mobile Communi- cations Business		Internet Business		International Fixed Communi- cations Business		Others		Total
	NT$		NT$		NT$		NT$		NT$		NT$
	(In Millions)
Main Products and Service Revenues
Mobile services revenue	$	—	$	58,703	$	—	$	—	$	—	$	58,703
Sales of products		1,957		35,545		41		265		3,785		41,593
Local telephone and domestic long distance telephone    services revenue		27,929		—		—		—		—		27,929
Broadband access and domestic leased line services    revenue		22,116		—		—		—		—		22,116
Data Communications internet services revenue		—		—		21,003		—		—		21,003
International network and leased telephone services    revenue		—		—		—		7,066		—		7,066
Others		13,064		1,142		8,790		4,144		810		27,950
	$	65,066	$	95,390	$	29,834	$	11,475	$	4,595	$	206,360

Summary of Contract Balances

b. Contract balances

	December 31
	2018			2019
	NT$			NT$
	(In Millions)
Trade notes and accounts receivable (Note 10)	$	30,076		$	26,408
Contract assets
Products and service bundling	$	7,123		$	6,943
Other		109			116
Less : Loss allowance		(19	)		(17	)
	$	7,213		$	7,042
Current	$	4,869		$	4,441
Noncurrent		2,344			2,601
	$	7,213		$	7,042
Contract liabilities
Telecommunications business	$	8,193		$	12,772
Project business		4,508			10,360
Products and service bundling		106			39
Other		476			510
	$	13,283		$	23,681
Current	$	10,688		$	16,840
Noncurrent		2,595			6,841
	$	13,283		$	23,681

Summary of Changes in Contract Assets and Contract Liabilities

Significant changes of contract assets and liabilities recognized resulting from product and service bundling were as follows:

	Year Ended December 31
	2018			2019
	NT$			NT$
	(In Millions)
Contract assets
Net increase of customer contracts	$	4,126		$	6,066
Reclassified to trade receivables		(7,532	)		(6,405	)
	$	(3,406	)	$	(339	)
Contract liabilities
Net increase of customer contracts	$	16		$	22
Recognized as revenues		(194	)		(89	)
	$	(178	)	$	(67	)

Summary of Revenue Recognized

Revenue recognized for the period that was included in the contract liability at the beginning of the period was as follows:

	Year Ended December 31
	2018		2019
	NT$		NT$
	(In Millions)
Telecommunications business	$	7,157	$	6,186
Project business		627		3,973
Others		324		404
	$	8,108	$	10,563

Summary of Incremental Costs of Obtaining Contracts

c. Incremental costs of obtaining contracts

	December 31
	2018		2019
	NT$		NT$
	(In Millions)
Noncurrent
Incremental costs of obtaining contracts	$	1,335	$	943