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General Information - Summary of Consolidated Subsidiaries (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Jan. 01, 2018 | Jan. 01, 2017
Disclosure of subsidiaries [line items] |  |  |  |  |
Total assets | ₩ 32,474,120 | ₩ 29,895,721 |  | ₩ 31,252,689 | ₩ 30,814,580
Total liabilities | 17,815,630 | 16,712,367 |  | ₩ 17,062,496 | ₩ 17,897,638
Operating revenues | 23,436,050 | 23,546,929 | ₩ 23,164,202 |  |
Profit (loss) for the year | ₩ 719,412 | ₩ 546,341 | ₩ 831,845 |  |
KT Powertel Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Powertel Co., Ltd. | KT Powertel Co., Ltd. | KT Powertel Co., Ltd. |  |
Total assets | ₩ 124,064 | ₩ 115,125 | ₩ 113,725 |  |
Type of Business | Trunk radio system business |  |  |  |
Total liabilities | ₩ 28,217 | 18,937 | 19,899 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 65,620 | ₩ 69,234 | 81,390 |  |
Controlling percentage ownership | 44.80% | 44.80% |  |  |
Profit (loss) for the year | ₩ (5,545) | ₩ 2,112 | ₩ 202 |  |
Closing month | December |  |  |  |
KT Linkus Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Linkus Co., Ltd. | KT Linkus Co., Ltd. | KT Linkus Co., Ltd. |  |
Total assets | ₩ 54,147 | ₩ 59,344 | ₩ 64,318 |  |
Type of Business | Public telephone maintenance |  |  |  |
Total liabilities | ₩ 44,895 | 51,516 | 56,953 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 106,337 | ₩ 112,043 | 117,587 |  |
Controlling percentage ownership | 92.40% | 91.40% |  |  |
Profit (loss) for the year | ₩ 1,216 | ₩ 725 | ₩ (3,830) |  |
Closing month | December |  |  |  |
KT Submarine Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Submarine Co., Ltd. | KT Submarine Co., Ltd. | KT Submarine Co., Ltd. |  |
Total assets | ₩ 130,715 | ₩ 142,797 | ₩ 156,993 |  |
Type of Business | Submarine cable construction and maintenance |  |  |  |
Total liabilities | ₩ 27,530 | 34,056 | 55,573 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 61,652 | ₩ 73,985 | 84,137 |  |
Controlling percentage ownership | 39.30% | 39.30% |  |  |
Profit (loss) for the year | ₩ (4,286) | ₩ 8,243 | ₩ 5,146 |  |
Closing month | December |  |  |  |
KT Telecop Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Telecop Co., Ltd. | KT Telecop Co., Ltd. | KT Telecop Co., Ltd. |  |
Total assets | ₩ 272,492 | ₩ 264,353 | ₩ 265,553 |  |
Type of Business | Security service |  |  |  |
Total liabilities | ₩ 140,314 | 131,633 | 132,344 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 328,262 | ₩ 317,591 | 315,948 |  |
Controlling percentage ownership | 86.80% | 86.80% |  |  |
Profit (loss) for the year | ₩ 166 | ₩ 2,885 | ₩ 143 |  |
Closing month | December |  |  |  |
KT Hitel Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Hitel Co., Ltd. | KT Hitel Co., Ltd. | KT Hitel Co., Ltd. |  |
Total assets | ₩ 272,708 | ₩ 258,240 | ₩ 249,202 |  |
Type of Business | Data communication |  |  |  |
Total liabilities | ₩ 66,043 | 52,943 | 46,941 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 279,117 | ₩ 227,884 | 198,994 |  |
Controlling percentage ownership | 67.10% | 67.10% |  |  |
Profit (loss) for the year | ₩ 657 | ₩ 3,225 | ₩ 4,298 |  |
Closing month | December |  |  |  |
KT service bukbu Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Service Bukbu Co., Ltd. | KT Service Bukbu Co., Ltd. | KT Service Bukbu Co., Ltd. |  |
Total assets | ₩ 30,599 | ₩ 29,281 | ₩ 32,863 |  |
Type of Business | Opening services of fixed line |  |  |  |
Total liabilities | ₩ 23,964 | 22,096 | 24,580 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 195,961 | ₩ 194,837 | 182,952 |  |
Controlling percentage ownership | 67.30% | 67.30% |  |  |
Profit (loss) for the year | ₩ (31) | ₩ 688 | ₩ 694 |  |
Closing month | December |  |  |  |
KT service nambu Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Service Nambu Co., Ltd. | KT Service Nambu Co., Ltd. | KT Service Nambu Co., Ltd. |  |
Total assets | ₩ 37,452 | ₩ 36,076 | ₩ 32,621 |  |
Type of Business | Opening services of fixed line |  |  |  |
Total liabilities | ₩ 27,939 | 26,412 | 24,282 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 230,088 | ₩ 232,996 | 218,602 |  |
Controlling percentage ownership | 77.30% | 77.30% |  |  |
Profit (loss) for the year | ₩ 160 | ₩ 875 | ₩ 772 |  |
Closing month | December |  |  |  |
KT Commerce Inc. [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Commerce Inc. |  |  |  |
Type of Business | B2C, B2B service |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
KT Strategic Investment Fund No.1 [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Strategic Investment Fund No.1 |  |  |  |
Type of Business | Investment fund |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
KT Strategic Investment Fund No.2 [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Strategic Investment Fund No.2 |  |  |  |
Type of Business | Investment fund |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
KT Strategic Investment Fund No.3 [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Strategic Investment Fund No.3 |  |  |  |
Type of Business | Investment fund |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
KT strategic investment fund number four [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Strategic Investment Fund No.4 |  |  |  |
Type of Business | Investment fund |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
BCVP Strategic Investment Fund Number One [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | BC-VP Strategic Investment Fund No.1 |  |  |  |
Type of Business | Investment fund |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 100.00% |  |  |  |
Closing month | December |  |  |  |
BC Card Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | BC Card Co., Ltd. | BC Card Co., Ltd. | BC Card Co., Ltd.1 |  |
Total assets | ₩ 3,722,379 | ₩ 4,048,263 | ₩ 3,651,065 |  |
Type of Business | Credit card business |  |  |  |
Total liabilities | ₩ 2,630,536 | 2,955,038 | 2,602,404 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 3,551,715 | ₩ 3,628,995 | 3,567,512 |  |
Controlling percentage ownership | 69.50% | 69.50% |  |  |
Profit (loss) for the year | ₩ 70,889 | ₩ 156,109 | ₩ 163,131 |  |
Closing month | December |  |  |  |
VP Inc. [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | VP Inc. |  |  |  |
Type of Business | Payment security service for credit card, others |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 50.90% | 50.90% |  |  |
Closing month | December |  |  |  |
H&C Network [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | H&C Network | H&C Network | H&C Network1 |  |
Total assets | ₩ 245,841 | ₩ 273,856 | ₩ 272,110 |  |
Type of Business | Call centre for financial sectors |  |  |  |
Total liabilities | ₩ 63,188 | 65,446 | 80,983 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 297,470 | ₩ 277,622 | 266,613 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ (15,944) | ₩ 16,104 | ₩ 14,749 |  |
Closing month | December |  |  |  |
BC Card China Co., Ltd. [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | BC Card China Co., Ltd. |  |  |  |
Type of Business | Software development and data processing |  |  |  |
Location | China |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
INITECH Co., Ltd. [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | INITECH Co., Ltd. |  |  |  |
Type of Business | Internet banking ASP and security solutions |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 58.20% | 58.20% |  |  |
Closing month | December |  |  |  |
Smartro Co., Ltd. [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Smartro Co., Ltd. |  |  |  |
Type of Business | VAN (Value Added Network) business |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 81.10% | 81.10% |  |  |
Closing month | December |  |  |  |
KTDS Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KTDS Co., Ltd. | KTDS Co., Ltd. | KTDS Co., Ltd.1 |  |
Total assets | ₩ 148,675 | ₩ 144,922 | ₩ 197,970 |  |
Type of Business | System integration and maintenance |  |  |  |
Total liabilities | ₩ 95,834 | 93,343 | 151,644 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 434,302 | ₩ 459,266 | 476,379 |  |
Controlling percentage ownership | 95.50% | 95.50% |  |  |
Profit (loss) for the year | ₩ 8,586 | ₩ 11,584 | ₩ 10,838 |  |
Closing month | December |  |  |  |
KT M Hows Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT M Hows Co., Ltd. | KT M Hows Co., Ltd. | KT M Hows Co., Ltd. |  |
Total assets | ₩ 60,197 | ₩ 42,738 | ₩ 28,539 |  |
Type of Business | Mobile marketing |  |  |  |
Total liabilities | ₩ 42,386 | 28,489 | 18,466 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 26,673 | ₩ 24,610 | 19,922 |  |
Controlling percentage ownership | 90.00% | 90.00% |  |  |
Profit (loss) for the year | ₩ 3,691 | ₩ 4,097 | ₩ 2,865 |  |
Closing month | December |  |  |  |
KT M&S Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT M&S Co., Ltd. | KT M&S Co., Ltd. | KT M&S Co., Ltd. |  |
Total assets | ₩ 228,073 | ₩ 242,388 | ₩ 247,854 |  |
Type of Business | PCS distribution |  |  |  |
Total liabilities | ₩ 207,740 | 231,151 | 227,507 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 791,652 | ₩ 734,420 | 724,144 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ 11,408 | ₩ (9,707) | ₩ (12,955) |  |
Closing month | December |  |  |  |
GENIE Music Corporation K T Music Corporation [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | GENIE Music Corporation(KT Music Corporation) |  |  |  |
Type of Business | Online music production and distribution |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 36.00% | 42.50% |  |  |
Closing month | December |  |  |  |
KT MOS Bukbu Co.,Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT MOS Bukbu Co., Ltd. |  |  |  |
Total assets | ₩ 14,121 |  |  |  |
Type of Business | Telecommunication facility maintenance |  |  |  |
Total liabilities | ₩ 10,571 |  |  |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 16,543 |  |  |  |
Controlling percentage ownership | 100.00% |  |  |  |
Profit (loss) for the year | ₩ (782) |  |  |  |
Closing month | December |  |  |  |
KTMOS Nambu Co.,Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT MOS Nambu Co., Ltd. |  |  |  |
Total assets | ₩ 14,313 |  |  |  |
Type of Business | Telecommunication facility maintenance |  |  |  |
Total liabilities | ₩ 8,927 |  |  |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 14,941 |  |  |  |
Controlling percentage ownership | 98.40% |  |  |  |
Profit (loss) for the year | ₩ (2,418) |  |  |  |
Closing month | December |  |  |  |
KT Skylife Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Skylife Co., Ltd. | KT Skylife Co., Ltd. | KT Skylife Co., Ltd.1 |  |
Total assets | ₩ 816,001 | ₩ 792,893 | ₩ 777,948 |  |
Type of Business | Satellite broadcasting business |  |  |  |
Total liabilities | ₩ 149,841 | 210,550 | 231,452 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 694,059 | ₩ 687,752 | 668,945 |  |
Controlling percentage ownership | 50.30% | 50.30% |  |  |
Profit (loss) for the year | ₩ 52,010 | ₩ 57,314 | ₩ 68,863 |  |
Closing month | December |  |  |  |
Skylife TV Co., Ltd. [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Skylife TV Co., Ltd. |  |  |  |
Type of Business | TV contents provider |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 92.60% | 92.60% |  |  |
Closing month | December |  |  |  |
KT Estate Inc. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Estate Inc. | KT Estate Inc. | KT Estate Inc.1 |  |
Total assets | ₩ 1,695,995 | ₩ 1,869,194 | ₩ 1,734,729 |  |
Type of Business | Residential building development and supply |  |  |  |
Total liabilities | ₩ 304,712 | 502,915 | 375,341 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 569,269 | ₩ 428,446 | 405,417 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ 51,854 | ₩ 52,416 | ₩ 46,815 |  |
Closing month | December |  |  |  |
KT AMC Co., Ltd. [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT AMC Co., Ltd. |  |  |  |
Type of Business | Asset management and consulting services |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
NEXR Co., Ltd. [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | NEXR Co., Ltd. |  |  |  |
Type of Business | Cloud system implementation |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
KTSB Data service [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KTSB Data service | KTSB Data service | KTSB Data service |  |
Total assets | ₩ 8,632 | ₩ 18,306 | ₩ 20,075 |  |
Type of Business | Data centre development and related service |  |  |  |
Total liabilities | ₩ 523 | 605 | 759 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 4,627 | ₩ 4,950 | 5,136 |  |
Controlling percentage ownership | 51.00% | 51.00% |  |  |
Profit (loss) for the year | ₩ (9,576) | ₩ (1,651) | ₩ (1,983) |  |
Closing month | December |  |  |  |
KT Sat Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Sat Co., Ltd. | KT Sat Co., Ltd. | KT Sat Co., Ltd. |  |
Total assets | ₩ 685,926 | ₩ 742,391 | ₩ 744,653 |  |
Type of Business | Satellite communication business |  |  |  |
Total liabilities | ₩ 173,513 | 220,804 | 253,041 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 137,186 | ₩ 147,649 | 144,594 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ 4,921 | ₩ 29,601 | ₩ 36,266 |  |
Closing month | December |  |  |  |
Nasmedia Co Ltd [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Nasmedia Co., Ltd. | Nasmedia Co., Ltd. | Nasmedia Co., Ltd. |  |
Total assets | ₩ 303,112 | ₩ 315,967 | ₩ 263,925 |  |
Type of Business | Online advertisement |  |  |  |
Total liabilities | ₩ 161,164 | 188,197 | 159,502 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 106,805 | ₩ 120,667 | 70,037 |  |
Controlling percentage ownership | 42.80% | 42.80% |  |  |
Profit (loss) for the year | ₩ 20,596 | ₩ 26,676 | ₩ 11,972 |  |
Closing month | December |  |  |  |
KT sports [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Sports Co., Ltd | KT Sports | KT Sports |  |
Total assets |  | ₩ 11,131 | ₩ 16,925 |  |
Type of Business | Management of sports group |  |  |  |
Total liabilities |  | 7,805 | 13,573 |  |
Location | Korea |  |  |  |
Operating revenues |  | ₩ 53,357 | 48,476 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year |  | ₩ (199) | ₩ (198) |  |
Closing month | December |  |  |  |
KT music contents fund no.1 [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Music Contents Fund No.1 | KT Music Contents Fund No.1 | KT Music Contents Fund No.1 |  |
Total assets | ₩ 14,092 | ₩ 13,804 | ₩ 10,592 |  |
Type of Business | Music contents investment business |  |  |  |
Total liabilities | ₩ 1,035 | 1,041 | 331 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 559 | ₩ 370 | 349 |  |
Controlling percentage ownership | 80.00% | 80.00% |  |  |
Profit (loss) for the year | ₩ 294 | ₩ (499) | ₩ 103 |  |
Closing month | December |  |  |  |
K T Music Contents Fund No.2 [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Music Contents Fund No.2 |  |  |  |
Type of Business | Music contents investment business |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
KT-Michigan global content fund [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT-Michigan Global Content Fund | KT-Michigan Global Content Fund | KT-Michigan Global Content Fund |  |
Total assets | ₩ 12,741 | ₩ 14,575 | ₩ 16,250 |  |
Type of Business | Content investment business |  |  |  |
Total liabilities |  | 147 | 163 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 869 | ₩ 159 | 133 |  |
Controlling percentage ownership | 88.60% | 88.60% |  |  |
Profit (loss) for the year | ₩ (670) | ₩ (426) | ₩ (514) |  |
Closing month | December |  |  |  |
Autopion Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Autopion Co., Ltd. | Autopion Co., Ltd. | Autopion Co., Ltd. |  |
Total assets | ₩ 8,838 | ₩ 6,306 | ₩ 6,163 |  |
Type of Business | Service for information and communication |  |  |  |
Total liabilities | ₩ 5,801 | 3,530 | 2,794 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 12,035 | ₩ 6,679 | 7,772 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ 453 | ₩ (618) | ₩ (409) |  |
Closing month | December |  |  |  |
KTCS Corporation [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KTCS Corporation | KTCS Corporation | KTCS Corporation1 |  |
Total assets | ₩ 350,280 | ₩ 348,334 | ₩ 322,768 |  |
Type of Business | Database and online information provider |  |  |  |
Total liabilities | ₩ 188,561 | 188,764 | 166,642 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 1,019,787 | ₩ 968,186 | 955,050 |  |
Controlling percentage ownership | 30.90% | 30.90% |  |  |
Profit (loss) for the year | ₩ 11,401 | ₩ 7,385 | ₩ 7,892 |  |
Closing month | December |  |  |  |
KTIS Corporation [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KTIS Corporation | KTIS Corporation | KTIS Corporation |  |
Total assets | ₩ 229,246 | ₩ 223,818 | ₩ 221,176 |  |
Type of Business | Database and online information provider |  |  |  |
Total liabilities | ₩ 68,997 | 62,569 | 63,871 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 451,532 | ₩ 438,597 | 436,914 |  |
Controlling percentage ownership | 30.10% | 30.10% |  |  |
Profit (loss) for the year | ₩ 7,900 | ₩ 8,337 | ₩ 9,991 |  |
Closing month | December |  |  |  |
KT M mobile [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT M mobile | KT M mobile | KT M mobile |  |
Total assets | ₩ 146,334 | ₩ 93,601 | ₩ 131,446 |  |
Type of Business | Special category telecommunications operator and sales of communication device |  |  |  |
Total liabilities | ₩ 35,335 | 21,453 | 20,369 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 172,674 | ₩ 159,684 | 112,532 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ (10,085) | ₩ (38,883) | ₩ (40,041) |  |
Closing month | December |  |  |  |
KT Investment Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Investment Co., Ltd. | KT Investment Co., Ltd. | KT Investment Co., Ltd.1 |  |
Total assets | ₩ 74,580 | ₩ 54,673 | ₩ 39,506 |  |
Type of Business | Technology business finance |  |  |  |
Total liabilities | ₩ 58,040 | 38,313 | 23,123 |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 8,095 | ₩ 8,794 | 10,130 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ 247 | ₩ (619) | ₩ (1,832) |  |
Closing month | December |  |  |  |
Whowho&Company Co., Ltd. [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Whowho&Company Co., Ltd. |  |  |  |
Type of Business | Software development and supply |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
PlayD Co., Ltd. (N Search Marketing Co., Ltd.) [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | PlayD Co., Ltd. (N Search Marketing Co., Ltd.) |  |  |  |
Type of Business | Advertising agency business |  |  |  |
Location | Korea |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
Next Connect PFV [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Next connect PFV |  |  |  |
Total assets | ₩ 385,769 |  |  |  |
Type of Business | Residential building development and supply |  |  |  |
Total liabilities | ₩ 34,370 |  |  |  |
Location | Korea |  |  |  |
Operating revenues | ₩ 143 |  |  |  |
Controlling percentage ownership | 100.00% |  |  |  |
Profit (loss) for the year | ₩ (12,449) |  |  |  |
Closing month | December |  |  |  |
KT Rwanda Networks Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Rwanda Networks Ltd. | KT Rwanda Networks Ltd. | KT Rwanda Networks Ltd. |  |
Total assets | ₩ 144,129 | ₩ 151,359 | ₩ 167,112 |  |
Type of Business | Network installation and management |  |  |  |
Total liabilities | ₩ 162,801 | 139,561 | 138,651 |  |
Location | Rwanda |  |  |  |
Operating revenues | ₩ 15,150 | ₩ 15,931 | 13,435 |  |
Controlling percentage ownership | 51.00% | 51.00% |  |  |
Profit (loss) for the year | ₩ (29,238) | ₩ (22,762) | ₩ (31,455) |  |
Closing month | December |  |  |  |
AOS Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | AOS Ltd. | AOS Ltd. | AOS Ltd. |  |
Total assets | ₩ 14,018 | ₩ 9,437 | ₩ 10,025 |  |
Type of Business | System integration and maintenance |  |  |  |
Total liabilities | ₩ 4,952 | 4,519 | 3,179 |  |
Location | Rwanda |  |  |  |
Operating revenues | ₩ 6,300 | ₩ 8,952 | 14,481 |  |
Controlling percentage ownership | 51.00% | 51.00% |  |  |
Profit (loss) for the year | ₩ (680) | ₩ (682) | ₩ (1,123) |  |
Closing month | December |  |  |  |
KT Belgium [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Belgium | KT Belgium | KT Belgium |  |
Total assets | ₩ 90,172 | ₩ 86,455 | ₩ 79,391 |  |
Type of Business | Foreign investment business |  |  |  |
Total liabilities | ₩ 1 | 8 | 7 |  |
Location | Belgium |  |  |  |
Operating revenues | ₩ 29 | ₩ 49 |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ (43) | ₩ (2) | ₩ (67) |  |
Closing month | December |  |  |  |
KT ORS Belgium [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT ORS Belgium | KT ORS Belgium | KT ORS Belgium |  |
Total assets | ₩ 6,709 | ₩ 1,769 | ₩ 2,013 |  |
Type of Business | Foreign investment business |  |  |  |
Total liabilities | ₩ 5 | 14 | 23 |  |
Location | Belgium |  |  |  |
Operating revenues |  | ₩ 10 |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ (46) | ₩ (10) | ₩ (46) |  |
Closing month | December |  |  |  |
Korea Telecom Japan Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Korea Telecom Japan Co., Ltd. | Korea Telecom Japan Co., Ltd. | Korea Telecom Japan Co., Ltd. |  |
Total assets | ₩ 1,326 | ₩ 1,554 | ₩ 3,592 |  |
Type of Business | Foreign telecommunication business |  |  |  |
Total liabilities | ₩ 2,910 | 2,788 | 5,374 |  |
Location | Japan |  |  |  |
Operating revenues | ₩ 1,965 | ₩ 2,772 | 5,122 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ (126) | ₩ 536 | ₩ (1,391) |  |
Closing month | December |  |  |  |
KBTO sp.zo.o. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KBTO sp.zo.o. | KBTO sp.zo.o. | KBTO sp.zo.o. |  |
Total assets | ₩ 1,364 | ₩ 3,311 | ₩ 1,166 |  |
Type of Business | Electronic communication business |  |  |  |
Total liabilities | ₩ 217 | 2,268 | 2,378 |  |
Location | Poland |  |  |  |
Operating revenues | ₩ 202 | ₩ 67 | 21 |  |
Controlling percentage ownership | 96.20% | 94.30% |  |  |
Profit (loss) for the year | ₩ (3,771) | ₩ (3,456) | ₩ (2,587) |  |
Closing month | December |  |  |  |
Korea Telecom China Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Korea Telecom China Co., Ltd. | Korea Telecom China Co., Ltd. | Korea Telecom China Co., Ltd. |  |
Total assets | ₩ 661 | ₩ 665 | ₩ 532 |  |
Type of Business | Foreign telecommunication business |  |  |  |
Total liabilities | ₩ 22 | 32 | 188 |  |
Location | China |  |  |  |
Operating revenues | ₩ 681 | ₩ 1,030 | 930 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ 10 | ₩ 348 | ₩ 60 |  |
Closing month | December |  |  |  |
KT Dutch B.V. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Dutch B.V. | KT Dutch B.V. | KT Dutch B.V. |  |
Total assets | ₩ 31,693 | ₩ 30,312 | ₩ 34,197 |  |
Type of Business | Super iMax and East Telecom management |  |  |  |
Total liabilities | ₩ 41 | 50 | 73 |  |
Location | Netherlands |  |  |  |
Operating revenues | ₩ 191 | ₩ 206 | 166 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ 105 | ₩ 169 | ₩ 85 |  |
Closing month | December |  |  |  |
Super iMax LLC [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Super iMax LLC | Super iMax LLC | Super iMax LLC |  |
Total assets | ₩ 4,150 | ₩ 3,449 | ₩ 10,308 |  |
Type of Business | Wireless high speed internet business |  |  |  |
Total liabilities | ₩ 4,528 | 4,886 | 6,734 |  |
Location | Uzbekistan |  |  |  |
Operating revenues | ₩ 4,845 | ₩ 7,314 | 10,759 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ (424) | ₩ (4,584) | ₩ (1,802) |  |
Closing month | December |  |  |  |
East Telecom LLC [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | East Telecom LLC | East Telecom LLC | East Telecom LLC |  |
Total assets | ₩ 16,590 | ₩ 11,672 | ₩ 31,885 |  |
Type of Business | Fixed line telecommunication business |  |  |  |
Total liabilities | ₩ 14,263 | 11,748 | 16,554 |  |
Location | Uzbekistan |  |  |  |
Operating revenues | ₩ 15,087 | ₩ 19,663 | 27,492 |  |
Controlling percentage ownership | 91.00% | 91.00% |  |  |
Profit (loss) for the year | ₩ 2,639 | ₩ (9,118) | ₩ 3,257 |  |
Closing month | December |  |  |  |
Korea Telecom America, Inc. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Korea Telecom America, Inc. | Korea Telecom America, Inc. | Korea Telecom America, Inc. |  |
Total assets | ₩ 4,218 | ₩ 3,694 | ₩ 4,464 |  |
Type of Business | Foreign telecommunication business |  |  |  |
Total liabilities | ₩ 832 | 791 | 1,306 |  |
Location | USA |  |  |  |
Operating revenues | ₩ 7,554 | ₩ 6,783 | 7,113 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ 350 | ₩ 109 | ₩ 181 |  |
Closing month | December |  |  |  |
PT. KT Indonesia [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | PT. KT Indonesia | PT. KT Indonesia | PT. KT Indonesia |  |
Total assets | ₩ 8 | ₩ 8 | ₩ 16 |  |
Type of Business | Foreign telecommunication business |  |  |  |
Location | Indonesia |  |  |  |
Controlling percentage ownership | 99.00% | 99.00% |  |  |
Profit (loss) for the year |  | ₩ (6) | ₩ (7) |  |
Closing month | December |  |  |  |
PT BC card Asia Pacific [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | PT. BC Card Asia Pacific |  |  |  |
Type of Business | Software development and supply |  |  |  |
Location | Indonesia |  |  |  |
Controlling percentage ownership | 99.90% | 99.90% |  |  |
Closing month | December |  |  |  |
KT Hongkong Telecommunications Co., Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Hongkong Telecommunications Co., Ltd. | KT Hongkong Telecommunications Co., Ltd. | KT Hongkong Telecommunications Co., Ltd. |  |
Total assets | ₩ 3,616 | ₩ 2,578 | ₩ 1,571 |  |
Type of Business | Fixed line communication business |  |  |  |
Total liabilities | ₩ 2,143 | 1,497 | 956 |  |
Location | Hong Kong |  |  |  |
Operating revenues | ₩ 9,990 | ₩ 7,304 | 1,568 |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Profit (loss) for the year | ₩ 351 | ₩ 494 | ₩ 120 |  |
Closing month | December |  |  |  |
KT Hong kong Limited [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Hong Kong Limited |  |  |  |
Type of Business | Foreign investment business |  |  |  |
Location | Hong Kong |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
Korea Telecom Singapore Pte.Ltd. [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Korea Telecom Singapore Pte. Ltd. |  |  |  |
Type of Business | Foreign investment business |  |  |  |
Location | Singapore |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
Texnoprosistem LLP [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Texnoprosistem LLP |  |  |  |
Type of Business | Fixed line internet business |  |  |  |
Location | Uzbekistan |  |  |  |
Controlling percentage ownership | 100.00% | 100.00% |  |  |
Closing month | December |  |  |  |
Nasmedia Thailand Company Limited [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | Nasmedia Thailand Company Limited |  |  |  |
Type of Business | Internet advertising solution |  |  |  |
Location | Thailand |  |  |  |
Controlling percentage ownership | 99.90% |  |  |  |
Closing month | December |  |  |  |
GENIE Music Corporation(KT Music Corporation) [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | GENIE Music Corporation (KT Music Corporation) | GENIE Music Corporation(KT Music Corporation) | GENIE Music Corporation (KT Music Corporation) |  |
Total assets | ₩ 221,559 | ₩ 139,686 | ₩ 110,080 |  |
Total liabilities | 75,827 | 48,512 | 41,953 |  |
Operating revenues | 171,314 | 156,163 | 111,450 |  |
Profit (loss) for the year | ₩ 6,374 | ₩ (3,401) | ₩ 8,235 |  |
KT Sports Co Ltd [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Sports Co., Ltd. |  |  |  |
Total assets | ₩ 9,560 |  |  |  |
Total liabilities | 6,376 |  |  |  |
Operating revenues | 55,565 |  |  |  |
Profit (loss) for the year | ₩ (154) |  |  |  |
KT music contents fund number two [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary | KT Music Contents Fund No.2 | KT Music Contents Fund No.2 |  |  |
Total assets | ₩ 7,629 | ₩ 7,500 |  |  |
Total liabilities | 281 | 11 |  |  |
Operating revenues | 150 |  |  |  |
Profit (loss) for the year | ₩ (142) | ₩ (11) |  |  |
KT Innoedu Co., Ltd. [Member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary |  |  | KT Innoedu Co., Ltd. |  |
Total assets |  |  | ₩ 6,477 |  |
Total liabilities |  |  | 7,259 |  |
Operating revenues |  |  | 15,599 |  |
Profit (loss) for the year |  |  | ₩ 103 |  |
NgeneBio [member] |  |  |  |  |
Disclosure of subsidiaries [line items] |  |  |  |  |
Subsidiary |  |  | NgeneBio |  |
Total assets |  |  | ₩ 6,361 |  |
Total liabilities |  |  | 4,733 |  |
Operating revenues |  |  | 244 |  |
Profit (loss) for the year |  |  | ₩ (1,833) |  |

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