Tax in South Korea

Who is the tax authority in Korea?

The National Tax Service (NTS) of Korea is the principal national tax authority, established in 1966 and operating as an external organ of the Ministry of Economy and Finance. NTS administers the Income Tax Act (소득세법, Sodeukseosebeop), the Corporate Tax Act, the Value Added Tax Act, the Inheritance and Gift Tax Act, the Comprehensive Real Estate Tax Act, and a network of allied statutes [SC1][SC2]. NTS operates through six Regional Tax Offices and roughly 130 District Tax Offices across the country. Korea Customs Service handles customs and excise. Local-government tax administrations handle the local-government taxes (acquisition tax, registration tax, local consumption tax) and the Local Resident Tax that piggybacks on national income and corporate tax. Tax disputes proceed through the Tax Tribunal, the Korean Tax Appeal Board, and the Korean courts (including the Supreme Court). Certified Tax Accountants (Sehak Sa) regulated under the Certified Tax Accountant Act and Certified Public Accountants regulated under the CPA Act are the principal credentialed tax-and-accounting professions.

What is the Korean tax year and the filing deadline?

The Korean tax year for individuals is the calendar year. The personal Comprehensive Income Tax return is filed in May of the following year, with payment due by 31 May (with limited extensions for filers facing disaster-area or other prescribed conditions) [SC3]. Year-End Tax Settlement (Yeonmaljeongsan, 연말정산) is the principal mechanism for salaried employees — employers reconcile the year's withholding against actual liability in February of the following year, producing a refund or top-up payment that is processed through the employee's salary in February or March. Salaried filers whose income is fully covered by Year-End Settlement and who have no other reportable income are not required to file a separate Comprehensive Income return. Quarterly interim payments apply for self-employed and large corporate filers. Companies file the Corporation Tax Return within three months of fiscal year-end. VAT returns are filed quarterly with payment due by the 25th of the month following the quarter-end.

How is Korean tax residency determined?

Under Article 1-2 of the Income Tax Act, an individual is a Korean tax resident if they have a domicile (juso, 주소) or a residence (geoso, 거소) in Korea for one year or more [SC8]. Domicile is the place where the individual maintains their family-life relationships and the centre of the individual's everyday economic interests. Residence is the place where the individual stays for a prolonged period without amounting to a domicile. The one-year threshold for residency triggers retroactive treatment of the period of presence. Korea operates a four-tier residency framework: Resident (taxed on worldwide income, with limited exceptions for short-term residents — see below), Non-Resident (taxed on Korean-source income only), Short-Term Foreign Resident (taxed on Korean-source income plus foreign-source income remitted to Korea, available to foreign residents who have not been a Korean resident for more than five of the last ten years), and Diplomat (specific exemptions). Treaty residency tie-breakers under Korea's bilateral DTCs apply where two jurisdictions both treat a person as resident.

Residents are taxed on worldwide income; non-residents on Korean-source income only. Short-Term Foreign Residents (the 5-of-10-years rule) are taxed on Korean-source income plus only the portion of foreign-source income remitted to Korea — a structurally favourable position for foreign workers in their first five years of Korean residency. Departure from Korea triggers exit-tax exposure on substantial-shareholding positions under Articles 118-9 to 118-13 ITA, with deferred-payment options.

How does Korean personal income tax work?

Korean personal income tax operates on an eight-band graduated bracket structure. Rates for 2025 are 6 percent up to KRW 14 million, 15 percent up to KRW 50 million, 24 percent up to KRW 88 million, 35 percent up to KRW 150 million, 38 percent up to KRW 300 million, 40 percent up to KRW 500 million, 42 percent up to KRW 1 billion, and 45 percent above [SC4]. The Local Resident Tax (Jibang Sodeukse, 지방소득세) is levied on top at 10 percent of the national income tax — effectively making the combined top marginal rate approximately 49.5 percent (45 percent + 10 percent of 45 percent). Specific deductions include the Standard Deduction (basic personal deduction, dependants' deductions), credit-card-and-debit-card-spending deduction (with a cap), education-and-medical-expenses deductions, mortgage-interest deduction on principal residence, and a National Pension contribution deduction.

Financial Investment Income Tax (FIIT) — a planned new tax on listed-securities capital gains — was scheduled to take effect from 1 January 2025 but has been further deferred to 2027 under the most recent legislative cycle [SC5]. Until FIIT takes effect, capital gains on most listed-equity holdings remain exempt for individual filers below substantial-holder thresholds. Real-estate capital gains are taxed under a separate schedule with rates that depend on holding period and number of properties held; multi-home owners face heightened rates intended as anti-speculation measures.

How does Korean corporate tax work?

Korean corporate income tax operates on a four-band progressive bracket structure for fiscal years beginning on or after 1 January 2023 (post-Yoon-government tax reform). Rates are 9 percent up to KRW 200 million of taxable income, 19 percent up to KRW 20 billion, 21 percent up to KRW 300 billion, and 24 percent above [SC4]. The Local Resident Tax is levied on top at 10 percent of the national corporate tax. Korea implemented the OECD Pillar Two Global Anti-Base Erosion (GloBE) rules through amendments to the International Tax Coordination Act with the Income Inclusion Rule applying for fiscal years beginning on or after 1 January 2024 and the Undertaxed Profits Rule deferred to 2025 onwards, for groups with consolidated revenue above EUR 750 million [SC5]. The Korean CFC regime under Article 17 of the International Tax Coordination Act and the participation-exemption regime for qualifying intra-group dividends operate alongside. The R&D tax credit (R&D 세액공제) provides reduced effective rates on qualifying R&D expenditure with sector and size differentiation.

How does indirect tax work in Korea?

Value Added Tax (VAT, 부가가치세) is the principal indirect tax — a 10 percent flat rate that has been in force since 1977 [SC4]. There is no reduced or super-reduced rate; the 0 percent rate applies to exports and a narrow set of supplies. Exempt supplies include unprocessed foodstuffs, public transportation, financial services, medical services, education, real-estate-transfer transactions, residential-property leases, and a small set of culture-and-arts supplies. The mandatory VAT registration threshold is KRW 0 — registration is generally required from the start of taxable activity, with the Simplified Tax Regime available for small operators with annual revenue under KRW 80 million (raised in stages). Cross-border digital services to Korean consumers by non-resident vendors are subject to VAT under the Electronic Service Provider regime in force since 2015 (for B2C digital services) and 2019 (expansion to non-domestic-server-located providers). The Special Excise Tax applies on specific categories including alcohol, tobacco, motor vehicles, gambling, and luxury goods.

How is crypto taxed in Korea?

Korea passed comprehensive crypto-taxation legislation in late 2020 with original effective date 1 January 2022, but the effective date has been deferred multiple times under successive legislative cycles. The current effective date is 1 January 2027 (further deferred from the prior 1 January 2025 schedule under the post-2024 budget law) [SC5]. Under the prospective regime, gains on the disposal of cryptoassets above an annual exemption of KRW 2.5 million (with a separate framework for non-resident filers) will be taxed at a flat 22 percent (20 percent national + 2 percent local) under the miscellaneous-income category. Until the regime takes effect, individual crypto disposals are not separately taxed in most cases — the long deferral has produced a structurally favourable interim position for Korean-resident crypto investors. Mining and staking rewards remain taxable as ordinary income (typically miscellaneous or business income) at fair market value on receipt under existing income-tax provisions. Receipt of crypto as employment income is taxable at fair market value on receipt under the Year-End Tax Settlement framework. The Financial Services Commission and the Financial Intelligence Unit regulate Virtual Asset Service Providers (VASPs) under the Specific Financial Information Act (Specified Financial Transaction Information Act).

How does Korea handle tax treaties?

Korea maintains a network of approximately 95 comprehensive Double Taxation Conventions in force, one of the larger Asian networks [SC5]. Most Korean treaties follow the OECD Model with Korea-specific reservations on the credit-versus-exemption method (Korea generally applies the credit method) and on technical-services source taxation. Korea signed and ratified the OECD Multilateral Instrument; the MLI's modifications, including the Principal Purpose Test, apply to many of Korea's covered DTCs for periods from 2020 onward. Foreign tax-credit relief is generally claimed under Article 57 of the Income Tax Act for individuals and Article 57 of the Corporate Tax Act for corporations. The Korean transfer-pricing framework under the International Tax Coordination Act mirrors OECD principles with Korea-specific safe-harbours and APA frameworks.

What are the common penalties and pitfalls for foreigners?

Late filing of a Comprehensive Income Tax return triggers a non-filing penalty of 20 percent of the tax due (raised in stages from the prior 10 percent rate) under Article 47-2 of the Framework Act on National Taxes [SC1]. Underreporting of income triggers an underreporting penalty of 10 percent (reasonable error) or 40 percent (intentional) under Article 47-3. Late payment of tax triggers interest at the published daily rate plus a payment-delay penalty. Penalties for tax-evasion offences under the Punishment of Tax Offences Act range from monetary fines to imprisonment for up to ten years for serious cases.

Common pitfalls for arrivals to Korea include: missing the Short-Term Foreign Resident framework's five-of-ten-years window for the favourable foreign-source-income remittance basis; assuming the FIIT delay continues indefinitely when legislative cycles can re-set the effective date; underestimating the breadth of the cross-border-digital-services VAT regime for Korean-targeted digital businesses; and missing the 10 percent Local Resident Tax surcharge in effective-rate computations. For complex residency, regime-elective, or cross-border scenarios, common approaches discussed by practitioners include consulting a credentialed Sehak Sa or CPA before relying on a single-test conclusion.