SEC Form 6-K filed by KT Corporation

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 OF

THE SECURITIES EXCHANGE ACT OF 1934

For the month of February 2025

Commission File Number 1-14926

KT Corporation

(Translation of registrant’s name into English)

90, Buljeong-ro,

Bundang-gu, Seongnam-si,

Gyeonggi-do,

Korea

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F ☒   Form 40-F ☐

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

2024 Earnings Release 2025. 02. | Investor Relations

Disclaimer This presentation has been prepared by KT Corp.(the “Company”) in accordance with K-IFRS. This presentation contains forward-looking statements, which are subject to risks, uncertainties, and assumptions. This presentation is being presented solely for your information and is subject to change without notice. No presentation or warranty, expressed or implied, is made and no reliance should be placed on the accuracy, actuality, fairness, or completeness of the information presented. The Company has applied new accounting standard of K-IFRS 1115 as of Jan 1st, 2018 and K-IFRS 1116 ‘Leases’ as of Jan 1st, 2019. There are no obligation to apply the new standard to previous financial statements. If you have any questions related to this material, please contact the IR department. Tel: +82-70-4193-4036

Contents 2024 Highlights Financial Highlights Business Overview Appendix

Record high annual revenue since listing driven by CT, real estate, AX 1 2024 Highlights Financials Record high annual revenue since listing driven by CT, real estate, AX (Unit: KRW) Cons. Revenue 26,431.2bn (YoY+0.2%) Sep. Revenue 18,579.7bn (YoY+1.1%) Operating 809 Operating Profit .5bn (YoY-50.9%) Profit 346.5bn (YoY-70.8%) * Excluding one-off expenses (KT: 986.3bn, Subsidiaries: 16bn) OP(Separate) 1,332.8bn (YoY +12.4%), OP(Consolidated)1,811.8bn (YoY +9.8%) Shareholder return KRW 500 per share4Q24 Share Buyback KRW 250 bn Dividend FY2024 Total DPS 2,000 won & Cancellation (Cancellation TBC, considering foreign limits) (Record date: Feb.28, 2025) Business Strategy 2025 Guidance: Consolidated Revenue of Over 28tr. AICT Company Transformation Value-Up Plan ✓B2B AX Growth through a strategic partnership ✓AICT Transformation: FY28 AI/IT rev. up 3xof 2023 with Microsoft✓Improve profitability through streamlining —Korea-customized Secure Public Cloud’25.03 & AI Model’25.06 low-profit businesses ✓CT/Media innovation based on AX✓Liquidate non-core assets ✓Innovation in tech capability(incl. AI specialists)✓Share buyback & cancellation of 1tr. until ‘28. —IT modernization, fostering AI specialists and consulting department \ 250bn will be executed in ‘25 4

Contents 1 2024 Highlights 2 Financial Highlights 3 Business Overview 4 Appendix

1 Income Statement • Revenue growth due to core CT, real estate, and DC growth • OP decreased by 50.9% due to one-off labor cost (Unit: KRW bn) 4Q23 3Q24 4Q24 QoQ YoY 2023 2024 YoY Operating Revenue 6,687.7 6,654.6 6,575.6 -1.2% -1.7% 26,376.3 26,431.2 0.2% Service Revenue 5,720.2 5,752.0 5,754.7 0.0% 0.6% 22,994.7 23,005.9 0.0% Sale of goods 967.4 902.7 820.9 -9.1% -15.1% 3,381.6 3,425.2 1.3% Operating Expense 6,422.0 6,190.5 7,230.7 16.8% 12.6% 24,726.5 25,621.7 3.6% Operating Income 265.6 464.1 -655.1 -241.2% -346.6% 1,649.8 809.5 -50.9% Margin 4.0% 7.0% -10.0% -16.8%p -13.9%p 6.3% 3.1% -3.2%p Margin1 4.6% 8.1% -11.4% -19.5%p -16.0%p 7.2% 3.5% -3.7%p Non-op. Income/Los -277.6 45.0 -321.9 — -325.7 -191.8 41.1% Income before taxes -11.9 509.1 -977.1 — 1,324.1 617.7 -53.3% Net Income -41.7 383.2 -736.6 — 988.7 450.1 -54.5% Margin -0.6% 5.8% -11.2% -17.0%p -10.6%p 3.7% 1.7% -2.0%p EBITDA 1,279.2 1,428.9 318.0 -77.7% -75.1% 5,459.9 4,687.2 -14.2% Margin 19.1% 21.5% 4.8% -16.6%p -14.3%p 20.7% 17.7% -3.0%p 1) OP Margin1 = Operating Income/Service Revenue 6

2 Operating Expenses • Op. expenses +3.6% YoY due to workforce restructuring despite decline in the selling and service costs (Unit: KRW bn) 4Q23 3Q24 4Q24 QoQ YoY 2023 2024 YoY Operating Expenses 6,422.0 6,190.5 7,230.7 16.8% 12.6% 24,726.5 25,621.7 3.6% Labor Cost 1,157.8 1,118.3 2,189.6 95.8% 89.1% 4,549.4 5,622.0 23.6% General Expense 2,843.7 2,692.6 2,791.2 3.7% -1.8% 10,871.1 10,866.2 0.0% —Depreciation 1,013.6 964.8 973.1 0.9% -4.0% 3,810.1 3,877.7 1.8% Cost of Service 725.5 699.8 667.5 -4.6% -8.0% 2,890.0 2,750.4 -4.8% Selling Expense 645.9 600.8 608.4 1.3% -5.8% 2,503.9 2,409.6 -3.8% Cost of Goods sold 1,049.1 1,078.9 974.0 -9.7% -7.2% 3,912.1 3,973.4 1.6% [Selling Expense (KT Separate)] (Unit: KRW bn) 4Q23 3Q24 4Q24 QoQ YoY 2023 2024 YoY Selling Expense 644.2 623.9 630.7 1.1% -2.1% 2,543.7 2,493.7 -2.0%

3 Balance Sheet • Net debt/equity ratio decreased by YoY -1.9%p (Unit: KRW bn) Dec 31, 2023 Sept 30, 2024 Dec 31, 2024 QoQ YoY Assets 42,710.0 42,750.4 41,880.0 -2.0% -1.9% Cash & Cash equivalents 2,879.6 3,953.9 3,729.5 -5.7% 29.5% Liabilities 24,148.9 23,564.0 23,850.4 1.2% -1.2% Borrowings 10,218.2 9,768.6 10,520.7 7.7% 3.0% Equity 18,561.1 19,186.4 18,029.5 -6.0% -2.9% Capital Stock 1,564.5 1,564.5 1,564.5 0.0% 0.0% Net Debt 7,338.6 5,814.7 6,791.2 16.8% -7.5% Debt / Equity 130.1% 122.8% 132.3% 9.5%p 2.2%p Net Debt / Equity 39.5% 30.3% 37.7% 7.4%p -1.9%p 131.1% 134.9% 130.1% 129.8% 132.3% 124.8% 127.0% 122.5% 121.5% 115.4% 127.3% 122.8% Debt/Equity Net Debt/Equity 42.9% 41.0% 46.6% 44.6% 37.4% 40.6% 38.5% 39.5% 38.5% 37.7% 33.5% 30.3%

• 2024 Total CAPEX Execution: KRW 2,299.9bn (KT Separate), KRW 823.5bn (Major Subsidiaries) (Unit: KRW bn) 3,452 3,533 3,319 813 3,123 692 907 824 ? Major Subsidiaries’ CAPEX Includes Finance, Media, Cloud/DC, 2,760 2,721 Real Estate, etc. 2,412 2,300 ? KT Separate CAPEX Access network, Backbone Network, 2021 2022 2023 2024 B2B and etc. KT Major Subsidiaries

Contents 1 2024 Highlights 2 Financial Highlights 3 Business Overview 4 Appendix

1 KT—Wireless • Wireless service revenue +1.7% YoY with increased 5G penetration (77.8%) and MVNO/roaming • Expanded customer choice with mid-tier and online-only plans and strengthened online marketing (Unit: KRW bn) 4Q23 3Q24 4Q24 QoQ YoY 2023 2024 YoY Wireless 1,732.2 1,740.4 1,717.8 -1.3% -0.8% 6,869.6 6,959.9 1.3% Wireless Service 1,646.4 1,656.5 1,648.8 -0.5% 0.1% 6,522.7 6,633.1 1.7% Interconnection 85.7 83.9 69.0 -17.8% -19.5% 346.9 326.8 -5.8% Wireless Subscribers (Unit: Thousands) 26,132 24,897 24,834 24,904 25,199 10,251 10,400 9,722 9,948 10,093 2,969 Handset(5G) 3,795 3,519 3,364 3,184 Handse(exc. 5G) 4,242 4,276 4,313 4,562 5,581 2nd device & IoT 7,138 7,091 7,134 7,203 7,182 4Q23 1Q24 2Q24 3Q24 4Q24

2 KT—Fixed Line • Broadband rev. +1.1% YoY, due to increase in GiGA subscribers and value-added services • Media rev. +1.2% YoY, driven by premium subs. expansion and increase in high-quality STB (Unit: KRW bn) 4Q23 3Q24 4Q24 QoQ YoY 2023 2024 YoY Fixed Line 1,311.4 1,312.6 1,317.1 0.3% 0.4% 5,271.1 5,268.8 0.0% Broadband 620.3 622.2 625.4 0.5% 0.8% 2,460.0 2,486.9 1.1% Media 507.8 518.2 523.2 1.0% 3.0% 2,057.1 2,082.6 1.2% Home Telephony 183.3 172.2 168.6 -2.1% -8.0% 754.1 699.4 -7.3% Broadband Subscribers IPTVSubscribers (Unit: Thousands) (Unit: Thousands) Subscribers GiGA (%) 9,928 9,956 9,440 9,449 9,827 9,862 9,899 9,418 9,423 9,409 68.5% 68.7% 68.9% 69.2% 68.3% 4Q23 1Q24 2Q24 3Q24 4Q24 4Q23 1Q24 2Q24 3Q24 4Q24 12

3 KT—B2B Services • B2B Service rev. +2.9% YoY, led by growth of service-based businesses including AX platform and Corp. broadband • Continued to streamline low-margin businesses (Unit: KRW bn) 4Q23 3Q24 4Q24 QoQ YoY 2023 2024 YoY B2B Service 813.1 926.4 856.5 -7.5% 5.3% 3,460.4 3,560.6 2.9% Real Estate, etc. 84.6 89.6 104.3 16.4% 23.3% 331.3 364.1 9.9% Corp.Broadband/Data Revenue Revenue of AI/IT (Unit: KRW bn) (Unit: KRW bn) 1,276.5 1,299.7 1,105.8 1,218.9 YoY +1.8% YoY +11.9% 986.8 988.1 2022 2023 2024 2022 2023 2024 ? Corp. Broadband/Data rev includes: ? AI/IT rev includes: Leased line, Kornet, VPN, Global data AX platform-based including AICC, IoT, Multi/Hybrid Cloud, and Smart Mobility 13

4 Major Subsidiaries • kt cloud rev. +15.5% YoY, due to strong demand for data centers and increased CDN1) traffic 1) Content Delivery Network • kt estate rev. +1.7% YoY, due to steady growth of hotel and office rentals Revenue of Major Subsidiaries (consolidated) (Unit: KRW bn) 4Q23 3Q24 4Q24 QoQ YoY 2023 2024 YoY BC Card 1,026.9 931.4 961.1 3.2% -6.4% 4,025.0 3805.8 -5.4% Skylife 262.2 256.9 257.0 0.0% -2.0% 1,038.7 1022.9 -1.5% Content 194.6 156.2 163.4 4.6% -16.0% 687.0 593.5 -13.6% Subsidiaries2) kt cloud 182.1 207.0 221.0 6.8% 21.3% 678.3 783.2 15.5% KT Estate 194.0 147.5 165.9 12.5% -14.5% 594.5 604.9 1.7% 2) Nasmedia(PlayD incl.), KTStudiogenie(Genie music,Storywiz, and others incl.) Subsidiaries’ OP Contribution (Unit: KRW bn) 464.3 462.8 135.1 125.2 112.7 89.9 69.3 4Q23 1Q24 2Q24 3Q24 4Q24 2023 2024 14

Contents 1 2024 Highlights 2 Financial Highlights 3 Business Overview 4 Appendix

1 K-IFRS Income Statement (Unit: KRW bn) Consolidated 4Q23 1Q24 2Q24 3Q24 4Q24 2023 2024 KTSeparate 4Q 23 1Q24 2Q24 3Q24 4Q24 2023 2024 Operating revenue 6,687.7 6,654.6 6,546.4 6,654.6 6,575.6 26,376.3 26,431.2 Operating revenue 4,592.0 4,694.8 4,548.3 4,765.0 4,571.6 18,371.4 18,579.7 Service revenue 5,720.2 5,722.7 5,776.6 5,752.0 5,754.7 22,994.7 23,005.9 Service revenue 3,941.2 4,040.6 4,048.0 4,069.0 3,995.8 15,932.4 16,153.4 Sale of goods 967.4 931.9 769.8 902.7 820.9 3,381.6 3,425.2 Handset revenue 650.8 654.2 500.3 696.0 575.8 2,439.0 2,426.3 Operating expense 6,422.0 6,148.1 6,052.4 6,190.5 7,230.7 24,726.5 25,621.7 Operating expense 4,395.7 4,301.0 4,189.5 4,426.1 5,316.6 17,186.0 18,233.2 Cost of Service 5,372.9 5,101.2 5,178.9 5,111.6 6,256.7 20,814.4 21,648.3 Cost of Service 3,707.7 3,624.7 3,696.8 3,688.7 4,713.8 14,626.7 15,724.0 Labor cost 1,157.8 1,100.9 1,213.2 1,118.3 2,189.6 4,549.4 5,622.0 Labor cost 530.5 540.7 631.3 534.6 1,545.1 2,278.5 3,251.7 General expense 2,843.7 2,674.2 2,708.3 2,692.6 2,791.2 10,871.1 10,866.2 General expense 1,925.0 1,777.1 1,804.2 1,832.7 1,905.9 7,219.6 7,320.0 Cost of service 725.5 726.5 656.6 699.8 667.5 2,890.0 2,750.4 Cost of service 594.2 673.2 630.6 685.6 620.0 2,529.7 2,609.4 Selling expense 645.9 599.6 600.8 600.8 608.4 2,503.9 2,409.6 Selling expense 657.9 633.7 630.7 635.7 642.8 2,598.8 2,542.9 Cost of Goods sold 1,049.1 1,046.9 873.5 1,078.9 974.0 3,912.1 3,973.4 Cost of Devices sold 688.1 676.3 492.6 737.3 602.8 2,559.3 2,509.0 Operating income 265.6 506.5 494.0 464.1 -655.1 1,649.8 809.5 Operating income 196.3 393.8 358.8 338.9 -745.0 1,185.4 346.5 N-OP income (loss) -277.6 22.5 62.7 45.0 -321.9 -325.7 -191.8 N-OP income (loss) -91.6 72.4 50.3 69.2 -101.5 -30.1 90.3 N-OP income 105.8 323.1 325.8 35.8 589.7 788.6 1,274.5 N-OP income 50.0 309.0 260.0 32.5 538.7 703.0 1,140.1 N-OP expense 340.7 310.9 260.1 -11.1 915.0 1,070.9 1,474.8 N-OP expense 141.6 236.6 209.7 -36.7 640.2 733.1 1,049.8 Equity Method (G/ -42.7 10.2 -3.0 -1.9 3.3 -43.4 8.6 Income bf tax -11.9 529.0 556.7 509.1 -977.1 1,324.1 617.7 Income bf tax 104.8 466.1 409.2 408.0 -846.5 1,155.3 436.8 Income tax 29.7 136.0 146.2 125.9 -240.4 335.4 167.7 Income tax 7.0 112.1 94.7 98.2 -228.1 222.0 76.9 Net income -41.7 393.0 410.5 383.2 -736.6 988.7 450.1 Net income 97.8 354.0 314.5 309.8 -618.5 933.3 359.9 NI contribution to K 54.5 375.5 393.0 357.3 -622.6 1,009.9 503.3 EBITDA 1,279.2 1,480.2 1,460.2 1,428.9 318.0 5,459.9 4,687.2 EBITDA 1,031.5 1,199.1 1,162.9 1,144.8 70.4 4,368.7 3,577.2 EBITDA Margin 19.1% 22.2% 22.3% 21.5% 4.8% 20.7% 17.7% EBITDA Margin 22.5% 25.5% 25.6% 24.0% 1.5% 23.8% 19.3% 16

2 K-IFRS Balance Sheet (Unit: KRW bn) Consolidated 4Q23 1Q24 2Q24 3Q24 4Q24 KT Separate 4Q23 1Q24 2Q24 3Q24 4Q24 Assets 42,710.0 42,710.0 43,144.4 42,750.4 41,880.0 Assets 30,308.9 30,334.8 30,464.8 29,957.1 29,528.9 Current assets 14,518.2 14,997.4 15,175.2 15,197.0 14,252.0 Current assets 7,088.6 7,578.4 7,451.7 7,447.7 6,892.6 Cash & cash equivalents 2,879.6 3,000.7 3,786.7 3,953.9 3,729.5 Cash & cash equi. 1,242.0 1,331.6 1,722.5 1,608.7 1,540.6 Trade & other receivables 4,287.3 4,571.4 4,161.7 4,304.2 3,987.3 Trade & other rec. 3,190.3 3,546.3 3,097.6 3,275.6 2,904.8 Inventories 912.3 899.1 964.0 903.2 940.2 Inventories 368.1 310.3 404.1 264.6 224.7 Other current asset 6,438.9 6,526.2 6,262.7 6,035.7 5,595.0 Other current asset 2,288.2 2,390.2 2,227.5 2,298.8 2,222.5—Prepaid_Contract cost 1,252.1 1,249.2 1,233.6 1,236.7 1,233.6—Prepaid_Contract cost 1,340.2 1,335.4 1,312.5 1,318.3 1,308.8—Contract assets 581.8 620.4 611.1 625.6 577.4—Contract assets 535.8 540.2 548.6 542.0 521.1 Non-current assets 28,191.8 27,712.6 27,969.2 27,553.4 27,628.0 Non-current assets 23,220.4 22,756.4 23,013.1 22,509.4 22,636.3 Trade &other rec 451.7 381.2 398.4 357.0 381.8 Trade &other rec 370.7 298.8 321.1 278.2 309.1 Tangible assets 14,872.1 14,585.7 14,591.7 14,509.1 14,825.8 Tangible assets 11,492.8 11,214.3 11,264.4 11,185.6 11,477.7 Other current assets 12,868.1 12,745.7 12,979.1 12,687.3 12,420.4 Other current assets 10,380.2 10,281.4 10,472.9 10,116.8 9,953.2—Prepaid_Contract cost 475.4 465.1 471.4 485.2 504.6—Prepaid_Contract cost 464.2 451.9 453.8 475.3 493.4—Contract assets 240.1 229.3 226.3 225.3 223.4—Contract assets 219.1 207.4 204.1 201.7 198.2 Liabilities 24,148.9 24,127.8 24,162.5 23,564.0 23,850.4 Liabilities 15,265.4 15,335.6 15,166.7 14,513.1 15,075.7 Current liabilities 13,147.5 14,046.1 14,095.2 14,644.5 13,841.8 Current liabilities 6,957.5 7,477.8 7,315.1 8,074.9 7,600.2 Trade & other payables 8,054.9 8,282.4 8,052.3 7,712.9 7,361.8 Trade & other payables 4,459.0 4,864.3 4,694.7 4,421.5 4,552.8 Short -term borrowings 3,058.6 3,538.6 3,595.0 4,358.7 3,904.8 Short -term borrowings 1,725.2 1,914.9 1,789.5 2,860.3 2,434.2 Others 2,033.9 2,225.1 2,447.9 2,572.9 2,575.2 Others 773.3 698.5 830.8 793.0 613.2 —Contract liabilities 229.2 239.3 231.2 230.6 226.4—Contract liabilities 223.9 227.0 206.9 210.5 208.4 Non-current liabilities 11,001.4 10,081.7 10,067.3 8,919.5 10,008.7 Non-current liabilities 8,307.9 7,857.9 7,851.6 6,438.2 7,475.5 Trade & other payables 819.6 554.1 556.2 573.4 578.4 Trade & other payables 1,364.8 1,074.2 1,063.8 1,010.2 979.4 Long -term borrowings 7,159.6 6,612.8 6,555.6 5,409.9 6,615.9 Long -term borrowings 5,834.7 5,652.2 5,675.7 4,290.7 5,437.7 Others 3,022.3 2,914.8 2,955.4 2,936.2 2,814.3 Others 1,108.4 1,131.5 1,112.0 1,137.3 1,058.4 —Contract liabilities 49.6 48.7 43.6 48.7 46.9—Contract liabilities 35.8 36.0 26.4 32.9 34.5 Equity 18,561.1 18,582.2 18,981.9 19,186.4 18,029.5 Equity 15,043.5 14,999.2 15,298.1 15,444.1 14,453.2 Retained earnings 14,494.4 14,361.5 14,452.7 14,675.2 13,812.8 Retained earnings 12,544.4 12,390.5 12,404.2 12,579.2 11,750.9 17

3 Subscribers (Unit: Thousands) Wireless Subscribers 4Q 23 1Q 24 2Q 24 3Q 24 4Q 24 QoQ YoY Total 24,897 24,834 24,904 25,199 26,132 3.7% 5.0% —MNO 17,759 17,743 17,770 17,997 18,950 5.3% 6.7% —MVNO 7,138 7,091 7,134 7,203 7,182 -0.3% 0.6% 5G Handset 1) 9,722 9,948 10,093 10,251 10,400 1.5% 7.0% Churnrate2) 1.1% 1.1% 1.0% 1.0% 1.1% 0.1%p 0.0%p ARPU (KRW) 3) 34,302 34,461 34,507 34,560 34,567 0.0% 0.8% 1) 5G Handset : Retroactively applied from 1Q23 based on the change of subscriber disclosure criteria by the MSIT (excludes G 2nd 5 Device and 5G IoT) 2) Churn rate: Based on MNOsubscribers (excludes IoT) 3) ARPU = Wireless revenue* / Wireless subscribers** * Wireless revenue(3G, LTE, 5G incl.): Revenue of Voice/Data usage (Interconnection/Subscription fee exc.), VAS, Contract/ ndled Discounts, Bu and etc. incl. ** Wireless subscribers: Based on MSIT’s guidelines for average billed subscribers in quarter (IoT/M2M exc.) (Unit: Thousands) Fixed Line Subscribers 4Q 23 1Q 24 2Q 24 3Q 24 4Q 24 QoQ YoY Telephony 12,035 11,903 11,748 11,616 11,475 -1.2% -4.7% —PSTN 8,820 8,673 8,526 8,395 8,264 -1.6% -6.3% —VoIP 3,215 3,230 3,222 3,222 3,211 -0.3% -0.1% Broadband 9,827 9,862 9,899 9,928 9,956 0.3% 1.3% IPTV (GTV+GTS) 9,409 9,418 9,423 9,440 9,449 0.1% 0.4% ? Number of IPTV subscribers above differs from MSIT figures that follow the IPTV law —Number of KT pay TV subscribers in 2H 2024 is 8,852,093 (6-month average)

KT