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General Information - Summary of Consolidated Subsidiaries (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Disclosure of subsidiaries [Line Items] |  |  |
Total assets | ₩ 29,745,439 | ₩ 30,664,298 |
Total liabilities | 16,696,309 | 17,881,580 |
Operating revenues | 23,546,929 | 23,120,878 | ₩ 22,699,856
Profit (loss) for the year | ₩ 546,341 | ₩ 795,117 | ₩ 624,685
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 | ₩ 115,125 | ₩ 113,725 | ₩ 113,515
Type of Business | Trunk radio system business |  |
Total liabilities | ₩ 18,937 | 19,899 | 21,182
Location | Korea |  |
Operating revenues | ₩ 69,234 | ₩ 81,390 | 104,527
Controlling percentage ownership | 44.80% | 44.80% |
Profit (loss) for the year | ₩ 2,112 | ₩ 202 | ₩ (32,417)
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 | ₩ 59,344 | ₩ 64,318 | ₩ 77,141
Type of Business | Public telephone maintenance |  |
Total liabilities | ₩ 51,516 | 56,953 | 65,745
Location | Korea |  |
Operating revenues | ₩ 112,043 | ₩ 117,587 | 116,095
Controlling percentage ownership | 91.40% | 91.40% |
Profit (loss) for the year | ₩ 725 | ₩ (3,830) | ₩ 3,449
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 | ₩ 142,797 | ₩ 156,993 | ₩ 160,314
Type of Business | Submarine cable construction and maintenance |  |
Total liabilities | ₩ 34,056 | 55,573 | 63,518
Location | Korea |  |
Operating revenues | ₩ 73,985 | ₩ 84,137 | 67,268
Controlling percentage ownership | 39.30% | 39.30% |
Profit (loss) for the year | ₩ 8,243 | ₩ 5,146 | ₩ 4,145
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 | ₩ 264,353 | ₩ 265,553 | ₩ 269,191
Type of Business | Security service |  |
Total liabilities | ₩ 131,633 | 132,344 | 134,966
Location | Korea |  |
Operating revenues | ₩ 317,591 | ₩ 315,948 | 302,844
Controlling percentage ownership | 86.80% | 86.80% |
Profit (loss) for the year | ₩ 2,885 | ₩ 143 | ₩ (7,593)
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 | ₩ 258,240 | ₩ 249,202 | ₩ 235,757
Type of Business | Data communication |  |
Total liabilities | ₩ 52,943 | 46,941 | 33,938
Location | Korea |  |
Operating revenues | ₩ 227,884 | ₩ 198,994 | 162,155
Controlling percentage ownership | 67.10% | 67.10% |
Profit (loss) for the year | ₩ 3,225 | ₩ 4,298 | ₩ 7,258
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., Ltd2
Total assets | ₩ 29,281 | ₩ 32,863 | ₩ 31,879
Type of Business | Opening services of fixed line |  |
Total liabilities | ₩ 22,096 | 24,580 | 22,627
Location | Korea |  |
Operating revenues | ₩ 194,837 | ₩ 182,952 | 89,498
Controlling percentage ownership | 67.30% | 67.30% |
Profit (loss) for the year | ₩ 688 | ₩ 694 | ₩ (4,630)
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., Ltd2
Total assets | ₩ 36,076 | ₩ 32,621 | ₩ 20,729
Type of Business | Opening services of fixed line |  |
Total liabilities | ₩ 26,412 | 24,282 | 10,567
Location | Korea |  |
Operating revenues | ₩ 232,996 | ₩ 218,602 | 110,129
Controlling percentage ownership | 77.30% | 77.30% |
Profit (loss) for the year | ₩ 875 | ₩ 772 | ₩ (5,055)
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 New Business Fund No.1 [Member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | KT New Business Fund No. |  |
Type of Business | Investment fund |  |
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% |  |
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 | ₩ 4,048,263 | ₩ 3,651,065 | ₩ 2,963,952
Type of Business | Credit card business |  |
Total liabilities | ₩ 2,955,038 | 2,602,404 | 1,945,634
Location | Korea |  |
Operating revenues | ₩ 3,628,995 | ₩ 3,567,512 | 3,504,946
Controlling percentage ownership | 69.50% | 69.50% |
Profit (loss) for the year | ₩ 156,109 | ₩ 163,131 | ₩ 218,969
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 Network
Total assets | ₩ 273,856 | ₩ 272,110 | ₩ 248,189
Type of Business | Call centre for financial sectors |  |
Total liabilities | ₩ 65,446 | 80,983 | 70,635
Location | Korea |  |
Operating revenues | ₩ 277,622 | ₩ 266,613 | 241,008
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ 16,104 | ₩ 14,749 | ₩ 19,513
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.4 |  |
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.
Total assets | ₩ 144,922 | ₩ 197,970 | ₩ 162,518
Type of Business | System integration and maintenance |  |
Total liabilities | ₩ 93,343 | 151,644 | 116,654
Location | Korea |  |
Operating revenues | ₩ 459,266 | ₩ 476,379 | 423,015
Controlling percentage ownership | 95.50% | 95.50% |
Profit (loss) for the year | ₩ 11,584 | ₩ 10,838 | ₩ 12,836
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 | ₩ 42,738 | ₩ 28,539 | ₩ 25,093
Type of Business | Mobile marketing |  |
Total liabilities | ₩ 28,489 | 18,466 | 17,980
Location | Korea |  |
Operating revenues | ₩ 24,610 | ₩ 19,922 | 19,352
Controlling percentage ownership | 90.00% | 90.00% |
Profit (loss) for the year | ₩ 4,097 | ₩ 2,865 | ₩ 1,728
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 | ₩ 242,388 | ₩ 247,854 | ₩ 256,246
Type of Business | PCS distribution |  |
Total liabilities | ₩ 231,151 | 227,507 | 217,892
Location | Korea |  |
Operating revenues | ₩ 734,420 | ₩ 724,144 | 853,011
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ (9,707) | ₩ (12,955) | ₩ (18,776)
Closing month | December |  |
G E N I E 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 | 42.50% | 49.90% |
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.
Total assets | ₩ 792,893 | ₩ 777,948 | ₩ 711,294
Type of Business | Satellite broadcasting business |  |
Total liabilities | ₩ 210,550 | 231,452 | 217,850
Location | Korea |  |
Operating revenues | ₩ 687,752 | ₩ 668,945 | 668,521
Controlling percentage ownership | 50.30% | 50.30% |
Profit (loss) for the year | ₩ 57,314 | ₩ 68,863 | ₩ 72,987
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.
Total assets | ₩ 1,869,194 | ₩ 1,734,729 | ₩ 1,603,438
Type of Business | Residential building development and supply |  |
Total liabilities | ₩ 502,915 | 375,341 | 260,292
Location | Korea |  |
Operating revenues | ₩ 428,446 | ₩ 405,417 | 254,776
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ 52,416 | ₩ 46,815 | ₩ 27,487
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 | ₩ 18,306 | ₩ 20,075 | ₩ 23,063
Type of Business | Data centre development and related service |  |
Total liabilities | ₩ 605 | 759 | 1,730
Location | Korea |  |
Operating revenues | ₩ 4,950 | ₩ 5,136 | 4,390
Controlling percentage ownership | 51.00% | 51.00% |
Profit (loss) for the year | ₩ (1,651) | ₩ (1,983) | ₩ (2,444)
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 | ₩ 742,391 | ₩ 744,653 | ₩ 679,959
Type of Business | Satellite communication business |  |
Total liabilities | ₩ 220,804 | 253,041 | 210,110
Location | Korea |  |
Operating revenues | ₩ 147,649 | ₩ 144,594 | 133,326
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ 29,601 | ₩ 36,266 | ₩ 27,174
Closing month | December |  |
K T Innoedu Co [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | KT Innoedu Co |  | KT Innoedu Co., Ltd.
Total assets |  |  | ₩ 5,858
Type of Business | E-learning business |  |
Total liabilities |  |  | 7,585
Location | Korea |  |
Operating revenues |  |  | 18,156
Controlling percentage ownership |  | 96.80% |
Profit (loss) for the year |  |  | ₩ (4,288)
Closing month | December |  |
Nasmedia, Inc. [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | Nasmedia, Inc. | Nasmedia, Inc. | Nasmedia, Inc.
Total assets | ₩ 315,967 | ₩ 263,925 | ₩ 141,733
Type of Business | Online advertisement |  |
Total liabilities | ₩ 188,197 | 159,502 | 72,202
Location | Korea |  |
Operating revenues | ₩ 120,667 | ₩ 70,037 | 45,630
Controlling percentage ownership | 42.80% | 42.80% |
Profit (loss) for the year | ₩ 26,676 | ₩ 11,972 | ₩ 9,916
Closing month | December |  |
KT sports [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | KT Sports | KT Sports | KT Sports
Total assets | ₩ 11,131 | ₩ 16,925 | ₩ 15,341
Type of Business | Management of sports group |  |
Total liabilities | ₩ 7,805 | 13,573 | 11,643
Location | Korea |  |
Operating revenues | ₩ 53,357 | ₩ 48,476 | 51,801
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ (199) | ₩ (198) | ₩ (3,836)
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 | ₩ 13,804 | ₩ 10,592 | ₩ 10,206
Type of Business | Music contents investment business |  |
Total liabilities | ₩ 1,041 | 331 | 47
Location | Korea |  |
Operating revenues | ₩ 370 | ₩ 349 | 468
Controlling percentage ownership | 80.00% | 80.00% |
Profit (loss) for the year | ₩ (499) | ₩ 103 | ₩ (111)
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% |  |
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 | ₩ 14,575 | ₩ 16,250 | ₩ 5,401
Type of Business | Content investment business |  |
Total liabilities | ₩ 147 | 163 |
Location | Korea |  |
Operating revenues | ₩ 159 | ₩ 133 | 861
Controlling percentage ownership | 88.60% | 88.60% |
Profit (loss) for the year | ₩ (426) | ₩ (514) | ₩ (209)
Closing month | December |  |
Autopion Co., Ltd. [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | Autopion Co., Ltd. | Autopion Co., Ltd. | Autopion Co., Ltd.
Total assets | ₩ 6,306 | ₩ 6,163 | ₩ 7,102
Type of Business | Service for information and communication |  |
Total liabilities | ₩ 3,530 | 2,794 | 3,317
Location | Korea |  |
Operating revenues | ₩ 6,679 | ₩ 7,772 | 10,585
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ (618) | ₩ (409) | ₩ 1,123
Closing month | December |  |
KTCS Corporation [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | KTCS Corporation | KTCS Corporation | KTCS Corporation
Total assets | ₩ 348,334 | ₩ 322,768 | ₩ 346,949
Type of Business | Database and online information provider |  |
Total liabilities | ₩ 188,764 | 166,642 | 194,367
Location | Korea |  |
Operating revenues | ₩ 968,186 | ₩ 955,050 | 1,066,556
Controlling percentage ownership | 30.90% | 30.90% |
Profit (loss) for the year | ₩ 7,385 | ₩ 7,892 | ₩ 13,685
Closing month | December |  |
KTIS Corporation [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | KTIS Corporation | KTIS Corporation | KTIS Corporation
Total assets | ₩ 223,818 | ₩ 221,176 | ₩ 211,164
Type of Business | Database and online information provider |  |
Total liabilities | ₩ 62,569 | 63,871 | 55,370
Location | Korea |  |
Operating revenues | ₩ 438,597 | ₩ 436,914 | 473,892
Controlling percentage ownership | 30.10% | 30.10% |
Profit (loss) for the year | ₩ 8,337 | ₩ 9,991 | ₩ 15,041
Closing month | December |  |
KT M mobile [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | KT M mobile | KT M mobile | KT M mobile
Total assets | ₩ 93,601 | ₩ 131,446 | ₩ 64,756
Type of Business | Special category telecommunications operator and sales of communication device |  |
Total liabilities | ₩ 21,453 | 20,369 | 13,121
Location | Korea |  |
Operating revenues | ₩ 159,684 | ₩ 112,532 | 42,478
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ (38,883) | ₩ (40,041) | ₩ (36,725)
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
Total assets | ₩ 54,673 | ₩ 39,506 | ₩ 49,485
Type of Business | Technology business finance |  |
Total liabilities | ₩ 38,313 | 23,123 | 30,827
Location | Korea |  |
Operating revenues | ₩ 8,794 | ₩ 10,130 | 4,704
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ (619) | ₩ (1,832) | ₩ (219)
Closing month | December |  |
Ngen bio [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | NgenBio |  |
Type of Business | Medicine and Pharmacy development business |  |
Location | Belgium |  |
Controlling percentage ownership |  | 49.80% |
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 |  |
KT Rwanda Networks Ltd. [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | KT Rwanda Networks Ltd. | KT Rwanda Networks Ltd. | Olleh Rwanda Networks Ltd.
Total assets | ₩ 151,359 | ₩ 167,112 | ₩ 188,951
Type of Business | Network installation and management |  |
Total liabilities | ₩ 139,561 | 138,651 | 147,653
Location | Rwanda |  |
Operating revenues | ₩ 15,931 | ₩ 13,435 | 7,299
Controlling percentage ownership | 51.00% | 51.00% |
Profit (loss) for the year | ₩ (22,762) | ₩ (31,455) | ₩ (28,721)
Closing month | December |  |
AOS Ltd. [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | AOS Ltd. | AOS Ltd. | Africa Olleh Services Ltd.
Total assets | ₩ 9,437 | ₩ 10,025 | ₩ 11,928
Type of Business | System integration and maintenance |  |
Total liabilities | ₩ 4,519 | 3,179 | 12,187
Location | Rwanda |  |
Operating revenues | ₩ 8,952 | ₩ 14,481 | 8,712
Controlling percentage ownership | 51.00% | 51.00% |
Profit (loss) for the year | ₩ (682) | ₩ (1,123) | ₩ (923)
Closing month | December |  |
KT Belgium [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | KT Belgium | KT Belguium | KT Belgium
Total assets | ₩ 86,455 | ₩ 79,391 | ₩ 77,058
Type of Business | Foreign investment business |  |
Total liabilities | ₩ 8 | ₩ 7 | 4
Location | Belgium |  |
Operating revenues | ₩ 49 |  |
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ (2) | ₩ (67) | ₩ (127)
Closing month | December |  |
KT ORS Belgium [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | KT ORS Belgium | KT ORS Belgium | KT ORS Belgium
Total assets | ₩ 1,769 | ₩ 2,013 | ₩ 1,996
Type of Business | Foreign investment business |  |
Total liabilities | ₩ 14 | ₩ 23 | 20
Location | Belgium |  |
Operating revenues | ₩ 10 |  |
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ (10) | ₩ (46) | ₩ (75)
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 | ₩ 1,554 | ₩ 3,592 | ₩ 13,889
Type of Business | Foreign telecommunication business |  |
Total liabilities | ₩ 2,788 | 5,374 | 14,393
Location | Japan |  |
Operating revenues | ₩ 2,772 | ₩ 5,122 | 25,652
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ 536 | ₩ (1,391) | ₩ (248)
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 | ₩ 3,311 | ₩ 1,166 | ₩ 1,471
Type of Business | Electronic communication business |  |
Total liabilities | ₩ 2,268 | 2,378 | 1,817
Location | Poland |  |
Operating revenues | ₩ 67 | ₩ 21 |
Controlling percentage ownership | 94.00% | 75.00% |
Profit (loss) for the year | ₩ (3,456) | ₩ (2,587) | ₩ (328)
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 | ₩ 665 | ₩ 532 | ₩ 909
Type of Business | Foreign telecommunication business |  |
Total liabilities | ₩ 32 | 188 | 198
Location | China |  |
Operating revenues | ₩ 1,030 | ₩ 930 | 1,748
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ 348 | ₩ 60 | ₩ (95)
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 | ₩ 30,312 | ₩ 34,197 | ₩ 29,402
Type of Business | Super iMax and East Telecom management |  |
Total liabilities | ₩ 50 | 73 | 27
Location | Netherlands |  |
Operating revenues | ₩ 206 | ₩ 166 | 161
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ 169 | ₩ 85 | ₩ 118
Closing month | December |  |
Super iMax LLC [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | Super iMax LLC | Super iMax LLC | Super iMax LLC
Total assets | ₩ 3,449 | ₩ 10,308 | ₩ 14,962
Type of Business | Wireless high speed internet business |  |
Total liabilities | ₩ 4,886 | 6,734 | 8,186
Location | Uzbekistan |  |
Operating revenues | ₩ 7,314 | ₩ 10,759 | 8,291
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ (4,584) | ₩ (1,802) | ₩ (2,220)
Closing month | December |  |
East Telecom LLC [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | East Telecom LLC | East Telecom LLC | East Telecom LLC
Total assets | ₩ 11,672 | ₩ 31,885 | ₩ 30,833
Type of Business | Fixed line telecommunication business |  |
Total liabilities | ₩ 11,748 | 16,554 | 17,066
Location | Uzbekistan |  |
Operating revenues | ₩ 19,663 | ₩ 27,492 | 24,066
Controlling percentage ownership | 91.00% | 91.00% |
Profit (loss) for the year | ₩ (9,118) | ₩ 3,257 | ₩ 664
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 | ₩ 3,694 | ₩ 4,464 | ₩ 6,016
Type of Business | Foreign telecommunication business |  |
Total liabilities | ₩ 791 | 1,306 | 1,378
Location | USA |  |
Operating revenues | ₩ 6,783 | ₩ 7,113 | 6,391
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ 109 | ₩ 181 | ₩ 156
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 | ₩ 16 | ₩ 22
Type of Business | Foreign telecommunication business |  |
Location | Indonesia |  |
Controlling percentage ownership | 99.00% | 99.00% |
Profit (loss) for the year | ₩ (6) | ₩ (7) | ₩ (9)
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. |
Total assets | ₩ 2,578 | ₩ 1,571 |
Type of Business | Fixed line communication business |  |
Total liabilities | ₩ 1,497 | 956 |
Location | Hong Kong |  |
Operating revenues | ₩ 7,304 | ₩ 1,568 |
Controlling percentage ownership | 100.00% | 100.00% |
Profit (loss) for the year | ₩ 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 |  |
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 | ₩ 139,686 | ₩ 110,080 | ₩ 90,518
Total liabilities | 48,512 | 41,953 | 30,704
Operating revenues | 156,163 | 111,450 | 90,005
Profit (loss) for the year | ₩ (3,401) | ₩ 8,235 | ₩ 3,446
NgeneBio [Member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary |  | NgeneBio | NgeneBio
Total assets |  | ₩ 6,361 | ₩ 7,894
Total liabilities |  | 4,733 | 4,683
Operating revenues |  | 244 |
Profit (loss) for the year |  | ₩ (1,833) | ₩ (434)
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 |
KT music contents fund number two [member] |  |  |
Disclosure of subsidiaries [Line Items] |  |  |
Subsidiary | KT Music Contents Fund No.2 |  |
Total assets | ₩ 7,500 |  |
Total liabilities | 11 |  |
Profit (loss) for the year | ₩ (11) |  |

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