A major South Korean telecommunications and platform company, KT provides mobile phone service, broadband internet, and digital television through brands like Genie TV. It was founded in 1981 as the state-run Korea Telecommunications Authority, spun off from the government to modernize the country's phone network, and renamed KT Corporation in 2002. Its former brand "olleh" is simply the word "hello" spelled backward, chosen to signal a fresh, customer-first approach.
20-F · Fiscal year ended Dec 31, 2025 · SEC filing ↗
KT's operating profit rebounded to ₩2,529B in 2025 after a one-time retirement charge depressed the prior year.
rebounded sharply after last year's one-off retirement charge. rose 6.8% to ₩28,548B and operating income reached ₩2,529B as employee benefit costs fell by ₩1,035B, while a competitor's cybersecurity incident helped drive an 11.1% increase in mobile subscribers. A major security breach of its own in late 2025 now threatens to reverse those subscriber gains and will materially affect 2026 results.
Key takeaways
reached ₩2,529B, up from ₩388.6M in 2024, as the ₩956B special voluntary retirement program that depressed the prior year did not repeat, causing employee benefit costs to fall by ₩1,035B.
Total operating rose 6.8% to ₩28,548B, driven by a ₩1,491B increase in sale of goods from a Gwangjin-gu apartment project and higher mobile and IT service revenue.
Mobile services grew 3.7% to ₩7,586B, with total subscribers increasing 11.1% to 29.0 million, partly due to a competitor's cybersecurity incident, while rose 1.9%.
Section summaries
Quantitative and Qualitative Disclosures About Market Risk
Market risk arises from foreign exchange, interest rate, and equity price exposures, managed via derivatives under board-reported policies.
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Foreign exchange risk stems from foreign-currency liabilities and anticipated payments, hedged with currency swaps and forwards.
A 10% Won strengthening against all currencies would have cut pre-tax income by W9 billion and total equity by W9 billion as of Dec 31, 2025.
The ICT 's more than tripled to ₩1,457B, and the satellite TV segment swung to a ₩26B profit from a ₩70B loss the prior year.
A December 2025 femtocell security breach leaked approximately 22,227 subscribers' personal data and caused over 233,000 service terminations, with the company stating it will materially affect 2026 results.
The July 2025 repeal of the Mobile Device Distribution Improvement Act permits greater handset subsidies, which the company expects will increase competitive intensity and marketing expenses.
What changed
The rebounded from 2.2% in 2024 to 8.9% in 2025, settling the prior year's watch item of whether margins would return toward the 5% level once the ₩956B voluntary retirement charge passed.
The ratio, flagged as a concern after rising to 134% in 2024, was not explicitly updated, but fell a further 14.4% to ₩12.2B, suggesting remains elevated.
IT and data center services , central to the AI-driven ICT transformation strategy, continued to grow, contributing to the 6.8% overall revenue increase, though a specific growth rate was not isolated in this filing.
The competitive threat from a fourth mobile provider, Stage X, expected to enter in 2025, was not mentioned in this filing; instead, competitive intensity is now expected to rise from the repeal of the handset subsidy law.
What to watch
The financial and subscriber impact of the December 2025 femtocell security breach, including the cost of regulatory penalties and the net effect on the mobile subscriber base after the initial 233,000 terminations.
The outcome of the 2026 bandwidth license reallocation for the 900 MHz, 1.8 GHz, and 2.1 GHz bands, and the size of the additional payments required.
The trajectory of marketing expenses and subscriber acquisition costs following the July 2025 repeal of the Mobile Device Distribution Improvement Act.
Whether the increase in employee benefit costs from the Supreme Court's expanded 'ordinary wages' ruling offsets the cost savings from the 2024 retirement program.
Interest rate risk is managed by balancing fixed and floating rate debt and using interest rate and combined swaps.
A 100 rate rise would have reduced pre-tax income by W7.0 billion and total equity by W2 billion as of Dec 31, 2025.
Equity price risk from marketable securities is unhedged; a 10% index drop would have lowered total equity by W195 billion as of Dec 31, 2025.
KT faces intense competition, regulatory shifts, a major 2025 cybersecurity breach, and macroeconomic risks that could materially affect operations.
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A December 2025 security breach leaked ~22,227 subscribers' personal data and caused over 233,000 service terminations, with ongoing regulatory investigations and expected adverse 2026 results.
The July 2025 repeal of the Mobile Device Distribution Improvement Act permits greater handset subsidies, likely increasing competitive intensity and marketing expenses.
KT's 3G and 4G LTE bandwidth licenses (900 MHz, 1.8 GHz, 2.1 GHz bands) are up for reallocation in 2026, requiring substantial additional payments and compliance with new requirements.
KT and SK Telecom remain designated as market-dominating entities, subjecting KT's local telephone rate changes to government objection and exposing it to fair-trade compliance reviews.
A December 2024 Supreme Court ruling redefined 'ordinary wages' to include regularly paid bonuses, increasing KT's employee benefit costs starting in the current fiscal year.
Macroeconomic and geopolitical risks, including North Korean tensions, Won , and potential U.S. tariffs on Korean exports, threaten KT's domestic-focused .
KT Corporation is Korea's leading integrated telecom and platform provider, operating mobile, fixed-line, media, financial, and other businesses, and pursuing an AI-driven ICT transformation.
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Mobile services generated 26.6% of 2025 with 29.0 million total subscribers, holding a 28.9% market share among mobile phone subscribers.
Fixed-line services contributed 18.2% of , where KT is the largest broadband provider (40.3% share) and holds a 51.7% share in local telephone and services.
Media/content (10.8% of ) includes (9.5M subs), satellite TV (3.2M subs), and digital music via Genie, while financial services (12.2%) are driven primarily by BC Card.
KT is transforming into an 'AX (AI Transformation) platform company,' integrating AI/IT into communications and expanding into cloud, IDC, and real estate development.
The company faces intense competition from SK Telecom and LG U+ across all major segments, and its local telephone rates are subject to regulatory objection as a designated market-dominating entity.
As of December 31, 2025, total operating was W28,548 billion, with handset and real estate sales accounting for 17.0% of the total.
Operating profit surged 295% to W2,529B in 2025 on revenue growth and a sharp drop in employee benefit costs.
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Total operating rose 6.8% to W28,548B, driven by a W1,491B jump in sale of goods from a Gwangjin-gu apartment project and higher mobile/IT service revenue.
Mobile services grew 3.7% to W7,586B as total subscribers increased 11.1% to 29.0M, partly from a competitor's cybersecurity incident, and rose 1.9%.
Operating expenses fell 0.2% to W26,019B, as a W1,035B drop in employee benefit costs (no repeat of 2024's W956B special retirement program) and lower losses offset higher sales commissions and service costs.
The ICT 's more than tripled to W1,457B, while the finance segment's income rose 6.2% to W152B and the satellite TV segment swung to a W26B profit.
was W4,942B; the company expects 2026 to remain at a similar level to 2025 and notes its September 2025 cybersecurity incident will materially affect 2026 results.