Tax Law in South Korea

Introduction

South Korean tax law is governed by the Framework Act on National Taxes (국세기본법, 1974) , the Corporate Tax Act (법인세법) , the Income Tax Act (소득세법) , the Value-Added Tax Act (부가가치세법) , and the Inheritance and Gift Tax Act (상속세 및 증여세법) . The National Tax Service (NTS) (국세청) administers tax collection. South Korea has a progressive tax system with relatively high top marginal rates and distinctive features in inheritance taxation.

Framework Act on National Taxes

The Framework Act establishes general principles of tax law:

• Tax liability: Taxes are imposed by statute — no taxation without law
• Tax avoidance: The substance-over-form principle (Article 14) allows the NTS to recharacterize transactions that lack economic substance
• Tax assessment and collection: Procedures for tax returns, audits, assessments, and collection
• Statute of limitations: Generally five years for tax assessment (10 years for tax evasion)

Income Tax Act

Individual Income Tax

The Income Tax Act taxes individuals on:

• Global income: Progressive rates from 6% to 45% (six brackets, 2024 rates)
• Capital gains: Separate taxation on real estate and securities gains
• Retirement income: Taxed separately at generally lower rates

Withholding and Reporting

Employers must withhold income tax from salaries. Self-employed individuals file quarterly preliminary returns and annual final returns.

Corporate Tax Act

The Corporate Tax Act taxes resident corporations on worldwide income:

• Tax rate: Progressive rates from 9% to 24% (three brackets, 2024 rates)
• Taxable income: Gross revenue less deductible expenses (generally all ordinary and necessary expenses)
• Dividend deduction: Deduction for dividends paid to promote profit distribution
• Consolidated taxation: Available for wholly-owned subsidiaries within a business group

International Taxation

• Transfer pricing: Arms-length principle applied to cross-border transactions
• Controlled Foreign Company (CFC) rules: Anti-deferral regime for foreign subsidiaries
• Double taxation relief: Foreign tax credit and tax treaty relief

Inheritance and Gift Tax

South Korea has one of the highest inheritance tax rates in the OECD:

• Progressive rates: 10% to 50% (four brackets, up to 60% for largest estates)
• Worldwide assets: Korean residents taxed on worldwide inheritance
• Gift tax: Applied to lifetime gifts (with annual exclusion of KRW 50 million)
• Valuation rules: Strict rules on business valuation for family business succession

Tax Appeal System

Taxpayers may challenge NTS assessments through:

1. Pre-assessment review: Internal NTS review
2. Tax Tribunal appeal: Independent Tax Tribunal review
3. Administrative litigation: Seoul Administrative Court then Supreme Court

The National Tax Tribunal (국세심판원) provides independent adjudication of tax disputes.

Conclusion

South Korean tax law features progressive taxation with high top rates, rigorous enforcement by the NTS, and a distinctive inheritance tax regime. Recent reforms have focused on reducing the corporate tax burden while expanding the tax base and strengthening international tax compliance.