Split View: 직장인을 위한 세금 기초: 연말정산부터 종합소득세까지 완벽 정리

Korean Tax Basics for Workers: A Complete Guide from Year-End Settlement to Comprehensive Income Tax

• Introduction
• 1. Basic Structure of Korean Income Tax
  • Types of Income
  • Income Tax Rate Structure (Progressive Tax)
  • Tax Calculation Flow
• 2. Understanding the 4 Major Social Insurances
  • Social Insurance Rates (Approximate, 2026 Basis)
  • Paycheck Deduction Calculation Example
• 3. Complete Guide to Year-End Settlement
  • What Is Year-End Settlement?
  • Year-End Settlement Timeline
  • Income Deduction vs. Tax Credit: The Key Difference
  • Major Income Deduction Items
  • Major Tax Credit Items
  • Credit Card Deduction Strategy
• 4. Optimizing Pension Account Tax Credits
  • Pension Account Comparison
  • Maximizing Tax Credit Strategy
• 5. Freelancer/Side Job Comprehensive Income Tax
  • When Comprehensive Income Tax Filing Is Required
  • Comprehensive Income Tax Timeline
  • Meaning of the 3.3% Freelancer Withholding
  • Business Income Expense Deduction
• 6. Investment Income Taxation
  • Financial Income Tax Framework
  • Foreign Stock Tax Calculation
  • Financial Income Comprehensive Taxation Threshold
• 7. Comprehensive Tax-Saving Strategy
  • Worker's Tax-Saving Checklist (By Priority)
  • Tax-Saving Strategy by Salary Range
  • ISA (Individual Savings Account) Utilization
• 8. Important Tax Calendar
  • Monthly Tax Schedule
  • Tax Points Developers Often Miss
• 9. Practical Q&A
  • Q1: What is the SME employee income tax reduction?
  • Q2: What about taxes when negotiating salary?
  • Q3: Is severance pay taxed?
• 10. Useful Tax Tools and Resources
  • Online Services
  • Tax Consultation
• Final Checklist: Tax Management for Workers
  • Monthly Tasks
  • Early Year (January-February) - Year-End Settlement
  • May - Comprehensive Income Tax (If Applicable)
  • Year-End (December) - Preparing for Next Year
• Quiz

Introduction

Every January and February, "year-end settlement" becomes a hot topic among Korean workers. Some receive a "13th month salary" (tax refund), while others end up owing additional taxes. This difference comes from understanding and preparing for taxes.

In this article, we comprehensively cover the basic tax structure Korean workers must know, year-end settlement strategies, the difference between income deductions and tax credits, comprehensive income tax for side jobs and freelancing, and taxation on investment income.

1. Basic Structure of Korean Income Tax

Types of Income

Under Korean tax law, individual income is broadly classified as follows:

Income Tax Rate Structure (Progressive Tax)

Korean income tax uses progressive tax rates. Higher income is taxed at higher rates, but not all income is taxed at the highest rate.

Progressive Tax Calculation Example:

If taxable income is 60M won:

Method 1: Calculate by bracket
- 14M won x 6% = 840K won
- (50M - 14M) x 15% = 5.4M won
- (60M - 50M) x 24% = 2.4M won
- Total: 8.64M won

Method 2: Using progressive deduction (simplified)
- 60M won x 24% - 5.76M won = 8.64M won

Local income tax: An additional 10% of the income tax is charged. Therefore, the effective rate is 1.1 times the rates above.

Tax Calculation Flow

Total Salary
 - Non-taxable Income (meal allowance, vehicle subsidies, etc.)
 ─────────────────────────
 = Gross Salary
 - Employment Income Deduction
 ─────────────────────────
 = Employment Income Amount
 - Various Income Deductions (personal, insurance, housing, etc.)
 ─────────────────────────
 = Taxable Income
 x Tax Rate
 ─────────────────────────
 = Calculated Tax
 - Tax Credits (children, pension, medical, education, etc.)
 ─────────────────────────
 = Determined Tax
 - Already Paid Tax (withheld amount)
 ─────────────────────────
 = Additional Payment or Refund

2. Understanding the 4 Major Social Insurances

Social Insurance Rates (Approximate, 2026 Basis)

Paycheck Deduction Calculation Example

Monthly salary of 4M won (pre-tax):

1. National Pension: 4M x 4.5% = 180K won
2. Health Insurance: 4M x 3.545% = 141.8K won
3. Long-term Care: 141.8K x 12.81% = 18.2K won
4. Employment Insurance: 4M x 0.9% = 36K won
5. Income Tax: approx. 70-90K won (varies by dependents, etc.)
6. Local Income Tax: 10% of income tax = approx. 7-9K won

Total deductions: approx. 450-470K won
Take-home pay: approx. 3.53-3.55M won

3. Complete Guide to Year-End Settlement

What Is Year-End Settlement?

It is the process of accurately settling taxes by reflecting actual income and deduction items against the taxes withheld monthly from your salary based on the simplified tax table.

• If you overpaid: Refund (the "13th month salary")
• If you underpaid: Additional payment (the "13th month tax bill")

Year-End Settlement Timeline

Income Deduction vs. Tax Credit: The Key Difference

Difference Illustrated:

Annual salary 60M won (taxable income bracket: 24%)

Effect of 1M won income deduction:
→ 1M won x 24% (applicable rate) = 240K won tax savings

Effect of 1M won tax credit:
→ 1M won directly subtracted from tax = 1M won tax savings

Conclusion: Tax credits are more direct and impactful

Major Income Deduction Items

Major Tax Credit Items

Credit Card Deduction Strategy

Credit card spending deduction is the most widely used item among workers.

Deduction amount = Total spending - (25% of gross salary)

Optimal Strategy:

1. Early year - First half: Fill the 25% threshold with credit cards (for point rewards)
2. Second half: Switch to debit cards/cash receipts (double the deduction rate)
3. Actively use traditional markets and public transportation

4. Optimizing Pension Account Tax Credits

Pension Account Comparison

Maximizing Tax Credit Strategy

For workers with gross salary under 55M won:

Pension savings 6M won + IRP 3M won = 9M won contribution
Tax credit: 9M won x 15% = 1.35M won refund

For workers with gross salary over 55M won:

Pension savings 6M won + IRP 3M won = 9M won contribution
Tax credit: 9M won x 12% = 1.08M won refund

5. Freelancer/Side Job Comprehensive Income Tax

When Comprehensive Income Tax Filing Is Required

• If you have income with 3.3% withholding as a freelancer
• If you have business income from side jobs
• If financial income (interest + dividends) exceeds 20M won annually
• If other income (lecture fees, manuscript fees, etc.) exceeds 3M won annually
• If you received employment income from 2 or more sources (without combined settlement)

Comprehensive Income Tax Timeline

Meaning of the 3.3% Freelancer Withholding

When contracting freelance work for 1M won:
- Withholding: 1M won x 3% (income tax) = 30K won
- Local income tax: 30K x 10% = 3K won
- Take-home: 967K won

This is merely "advance tax payment" — it's settled in the May comprehensive income tax filing.
- Actual tax < Withheld amount → Refund
- Actual tax > Withheld amount → Additional payment

Business Income Expense Deduction

Example expense items for developer freelancers:

• Laptop, monitor, and other equipment purchases
• Software license costs (IDE, cloud services, etc.)
• Internet/communication bills (business use portion)
• Transportation costs (client visits, etc.)
• Education expenses (work-related courses, seminars)
• Book purchases
• Co-working space/shared office fees
• Business-related meal expenses (entertainment)

6. Investment Income Taxation

Financial Income Tax Framework

Foreign Stock Tax Calculation

Foreign stock capital gain = Sale price - Purchase price - Fees
Tax = (Capital gain - 2.5M won) x 22%

Example:
- Purchase: 10M won
- Sale: 15M won
- Capital gain: 5M won
- Tax: (5M - 2.5M) x 22% = 550K won

Financial Income Comprehensive Taxation Threshold

When the combined total of interest income and dividend income exceeds 20M won annually, it is subject to comprehensive income tax filing combined with other income.

Example: Annual salary 70M won + Interest/dividend income 30M won

Up to 20M won: Separate taxation (15.4%)
Excess 10M won: Combined with employment income → Progressive rate applied
(Actual calculation is more complex, but the key point is that
rates increase when exceeding 20M won)

7. Comprehensive Tax-Saving Strategy

Worker's Tax-Saving Checklist (By Priority)

Essential (Everyone should do these):

• Max out pension savings + IRP tax credit limit (9M won)
• Strategic credit/debit card usage (exceed 25% threshold, then switch to debit)
• Apply for monthly rent tax credit (if eligible)
• Contribute to housing savings (houseless household head)
• Collect medical and education receipts

Additional (Situational):

• Collect donation receipts (religious organizations, NGOs, etc.)
• Apply for SME employee income tax reduction (if eligible, up to 70-90% for 5 years)
• Check insurance premium tax credit
• Verify housing subscription savings contributions
• Utilize foreign stock capital gains 2.5M won basic deduction (profit-loss netting)

Tax-Saving Strategy by Salary Range

ISA (Individual Savings Account) Utilization

8. Important Tax Calendar

Monthly Tax Schedule

Tax Points Developers Often Miss

• Foreign stock capital gains tax: Must be filed personally in May (unlike domestic stocks, not handled automatically)
• Side job/Freelance income: Even if 3.3% was withheld, comprehensive income tax filing is required in May
• Cryptocurrency tax: Check implementation timing (may be deferred)
• Foreign financial account reporting: Mandatory reporting in June if total overseas account balances exceed 500M won
• Stock option exercise: Taxed as employment income at exercise (market price - exercise price)

9. Practical Q&A

Q1: What is the SME employee income tax reduction?

Young people (aged 15-34), those 60+, people with disabilities, and career-interrupted women who are employed at SMEs can receive a 70-90% income tax reduction for 3-5 years from the employment date.

Q2: What about taxes when negotiating salary?

When your salary increases, the actual take-home increase may be less than expected due to tax rates.

Current salary 50M won → 60M won (10M won increase)

Expected take-home increase:
- Additional income tax: 10M x 24% = 2.4M won
- Local income tax: 240K won
- Social insurance increase: approx. 800K won
- Total additional deductions: approx. 3.44M won
- Actual take-home increase: approx. 6.56M won (65.6% of nominal raise)

Q3: Is severance pay taxed?

Yes, retirement income tax applies. However, there are deductions based on years of service, so the effective tax rate is low.

Severance → Years of service deduction → Converted salary → Tax rate applied → Retirement income tax

Years of service deduction:
- Up to 5 years: Years x 1M won
- Up to 10 years: 5M won + (Years-5) x 2M won
- Up to 20 years: 15M won + (Years-10) x 2.5M won
- Over 20 years: 40M won + (Years-20) x 3M won

10. Useful Tax Tools and Resources

Online Services

Tax Consultation

• National Tax Consultation Center: 126 (free)
• Tax Accountant Consultation: Korea Association of Tax Accountants (tax.or.kr)
• 3.3 (Ssamjeomssam): Simplified comprehensive income tax filing service

Final Checklist: Tax Management for Workers

Monthly Tasks

• Check pay stub (review deduction items)
• Verify cash receipt/card spending history

Early Year (January-February) - Year-End Settlement

• Download data from Hometax simplified service
• Manually add items not captured in the simplified service (donations, eyeglass purchases, etc.)
• Confirm dependent deduction eligibility
• Attach pension savings/IRP contribution certificate
• Prepare monthly rent tax credit documents (if applicable)
• Confirm SME youth reduction applied (if applicable)

May - Comprehensive Income Tax (If Applicable)

• File comprehensive income tax if you have side job/freelance income
• File foreign stock capital gains tax
• Organize expense receipts (freelancers)

Year-End (December) - Preparing for Next Year

• Max out pension savings/IRP contribution limit (by December 31)
• Review credit/debit card usage ratio
• Check ISA contribution limit
• Verify housing subscription savings contributions
• Request donation receipt issuance

Proper tax management is not just about saving money — it is the foundation for accurately understanding your financial situation and making rational financial decisions.

Quiz