- Authors
- Name
- Introduction
- 1. Basic Structure of Korean Income Tax
- 2. Understanding the 4 Major Social Insurances
- 3. Complete Guide to Year-End Settlement
- 4. Optimizing Pension Account Tax Credits
- 5. Freelancer/Side Job Comprehensive Income Tax
- 6. Investment Income Taxation
- 7. Comprehensive Tax-Saving Strategy
- 8. Important Tax Calendar
- 9. Practical Q&A
- 10. Useful Tax Tools and Resources
- Final Checklist: Tax Management for Workers
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 Type | Description | Taxation Method | Examples |
|---|---|---|---|
| Employment income | Salary from employment | Year-end settlement | Monthly salary, bonuses, performance pay |
| Business income | Income from business activities | Comprehensive income tax filing | Freelance work, self-employment income |
| Interest income | Interest from financial products | Withholding/Separate taxation | Deposit interest, bond interest |
| Dividend income | Stock dividends | Withholding/Separate taxation | Stock dividends, fund distributions |
| Pension income | Pension receipts | Pension income tax | National pension, retirement pension |
| Other income | Income not covered above | Withholding/Comprehensive taxation | Lecture fees, manuscript fees, lottery winnings |
| Capital gains | Profit from asset sales | Separate filing | Real estate, stock capital gains |
| Retirement income | Amount received upon retirement | Classified taxation | Severance pay, lump-sum retirement pension |
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.
| Taxable Income Bracket | Tax Rate | Progressive Deduction |
|---|---|---|
| Up to 14M won | 6% | - |
| 14M - 50M won | 15% | 1.26M won |
| 50M - 88M won | 24% | 5.76M won |
| 88M - 150M won | 35% | 15.44M won |
| 150M - 300M won | 38% | 19.94M won |
| 300M - 500M won | 40% | 25.94M won |
| 500M - 1B won | 42% | 35.94M won |
| Over 1B won | 45% | 65.94M won |
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)
| Insurance | Employee Share | Employer Share | Total | Notes |
|---|---|---|---|---|
| National Pension | 4.5% | 4.5% | 9% | Cap at 5.9M won monthly income |
| Health Insurance | 3.545% | 3.545% | 7.09% | Long-term care insurance separate |
| Long-term Care Insurance | 12.81% of health ins. | 12.81% of health ins. | - | Added on top of health insurance |
| Employment Insurance | 0.9% | 0.9-1.65% | 1.8-2.55% | Varies by company size |
| Industrial Accident Insurance | None | Varies by industry | - | Fully employer-paid |
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
| Timing | Action |
|---|---|
| From January 15 | NTS Hometax Simplified Service opens |
| January 15-31 | Review simplified data and prepare additional documents |
| Early February | Submit deduction documents to employer |
| February payroll | Refund or additional collection reflected |
| March 10 | Company's withholding tax filing deadline |
Income Deduction vs. Tax Credit: The Key Difference
| Category | Income Deduction | Tax Credit |
|---|---|---|
| Application timing | Before calculating taxable income | Subtracted from calculated tax |
| Effect | Lowers taxable income, potentially changing the tax bracket | Directly subtracted from the calculated tax amount |
| Advantageous for high earners | Yes, higher tax rate means bigger savings | Same amount regardless of tax rate |
| Examples | Personal, insurance, housing-related | Child credit, medical, education |
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
| Deduction Item | Limit | Conditions |
|---|---|---|
| Personal deduction (basic) | 1.5M won per person | Self, spouse, dependents (annual income under 1M won) |
| National Pension premiums | Full amount | Employee's share |
| Health insurance premiums | Full amount | Employee's share (including long-term care) |
| Housing rent loan principal & interest | Up to 4M won/year | Houseless household head, gross salary under 70M won |
| Housing savings | Up to 3M won/year (40% of deposits) | Houseless household head, gross salary under 70M won |
| Credit card spending | Exceeding 25% of gross salary | Card 15% / Cash receipt 30% / Traditional market 40% / Public transit 80% |
| Personal pension savings | Up to 720K won/year | Products enrolled before Dec 31, 2000 |
Major Tax Credit Items
| Credit Item | Rate/Limit | Conditions |
|---|---|---|
| Employment income tax credit | Varies by calculated tax | Automatically applied to workers |
| Child tax credit | 1 child: 150K, 2: 300K, 3+: 300K + 300K per additional child | Children eligible for basic deduction |
| Pension account tax credit | 12-15% of deposits (max 9M won) | IRP/Pension savings contributions |
| Insurance premium credit | 12% of premiums (max 1M won) | Insurance for basic deduction eligible persons |
| Medical expenses | 15% of amount exceeding 3% of gross salary | Self/dependent medical expenses |
| Education expenses | 15% of tuition paid | University 9M, K-12 3M, Self: full amount |
| Donations | 15-30% of donation amount | Statutory/designated donations |
| Monthly rent tax credit | 15-17% of rent (max 10M won) | Gross salary under 80M won, houseless |
Credit Card Deduction Strategy
Credit card spending deduction is the most widely used item among workers.
Deduction amount = Total spending - (25% of gross salary)
| Payment Method | Deduction Rate | Strategy |
|---|---|---|
| Credit card | 15% | Use credit cards up to 25% of gross salary (earn points) |
| Debit card/Cash receipt | 30% | Use debit cards beyond 25% (double the deduction rate) |
| Traditional markets | 40% | Buy at traditional markets when possible |
| Public transportation | 80% | Highest deduction rate for public transit |
Optimal Strategy:
- Early year - First half: Fill the 25% threshold with credit cards (for point rewards)
- Second half: Switch to debit cards/cash receipts (double the deduction rate)
- Actively use traditional markets and public transportation
4. Optimizing Pension Account Tax Credits
Pension Account Comparison
| Category | Pension Savings | IRP (Individual Retirement Pension) |
|---|---|---|
| Eligibility | Anyone | Workers, self-employed |
| Contribution limit | 18M won/year | 18M won/year (combined) |
| Tax credit limit | 6M won/year | 9M won/year (including pension savings) |
| Tax credit rate | Under 55M won gross: 15%, Over: 12% | Same |
| Early withdrawal | Possible (16.5% other income tax) | Restricted |
| Investment products | Funds, ETFs, deposits | Funds, ETFs, deposits, bonds, etc. |
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
| Timing | Content |
|---|---|
| May 1-31 | Comprehensive income tax filing and payment |
| November | Interim prepayment (half of previous year's tax) |
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
| Method | Description | Suitable For |
|---|---|---|
| Simple expense rate | Expenses recognized at NTS-determined rate | Small-scale freelancers (low income) |
| Standard expense rate | Major expenses with receipts, rest at determined rate | Income above certain threshold |
| Bookkeeping | Actual costs recorded in books | When expenses are high |
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
| Income Type | Taxation Method | Rate |
|---|---|---|
| Interest income | Withholding (separate taxation) | 15.4% (14% income tax + 1.4% local) |
| Dividend income | Withholding (separate taxation) | 15.4% |
| Combined financial income over 20M won | Comprehensive taxation | Progressive rates apply |
| Domestic stock capital gains (minor shareholders) | Non-taxable | 0% (excluding major shareholders) |
| Domestic stock capital gains (major shareholders) | Capital gains tax | 20-25% |
| Foreign stock capital gains | Capital gains tax | 22% (2.5M won basic deduction) |
| Cryptocurrency capital gains | Other income tax | 22% (2.5M won basic deduction, when implemented) |
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
| Salary Range | Key Strategy | Expected Savings |
|---|---|---|
| 30-50M won | Pension savings + debit card focus | 1-1.5M won |
| 50-70M won | Pension savings + IRP + housing savings | 1.5-2M won |
| 70M-100M won | Full IRP + donations + rent credit | 2-3M won |
| Over 100M won | ISA + IRP + long-term investment strategy | 3M+ won |
ISA (Individual Savings Account) Utilization
| Item | Details |
|---|---|
| Eligibility | Korean residents aged 19+ |
| Contribution limit | 20M won/year (100M won total) |
| Mandatory holding period | 3 years (different for subsidized/youth types) |
| Tax-free limit | Standard: 2M won, Subsidized/Youth: 4M won |
| Rate on excess | 9.9% (separate taxation) |
| Post-maturity transfer | Additional tax credit when transferred to IRP/pension savings (10%, max 3M won) |
8. Important Tax Calendar
Monthly Tax Schedule
| Month | Key Events |
|---|---|
| January | Year-end settlement simplified service opens (15th~), Withholding tax filing/payment |
| February | Year-end settlement document submission, Refund/additional collection reflected |
| March | Corporate tax filing (corporations), Withholding tax filing/payment |
| April | VAT preliminary filing (business owners) |
| May | Comprehensive income tax filing/payment (1st-31st) |
| June | Foreign financial account reporting (Jun 30) |
| July | VAT final filing (business owners), Property tax 1st installment |
| August | Resident tax payment |
| September | Property tax 2nd installment |
| October | - |
| November | Comprehensive income tax interim prepayment |
| December | Year-end settlement prep (review deduction items), Vehicle tax payment |
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.
| Category | Reduction Rate | Reduction Period | Annual Limit |
|---|---|---|---|
| Youth (15-34) | 90% | 5 years | 2M won |
| Age 60+ | 70% | 3 years | 2M won |
| Persons with disabilities | 70% | 3 years | 2M won |
| Career-interrupted women | 70% | 3 years | 2M won |
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
| Service | Purpose | URL |
|---|---|---|
| Hometax | Year-end settlement, comprehensive income tax filing | hometax.go.kr |
| Sontax | Hometax mobile app | App stores |
| NTS Simplified Service | Year-end settlement data lookup | Within Hometax |
| Wetax | Local tax lookup/payment | wetax.go.kr |
| 4 Social Insurance Information Center | Social insurance lookup | 4insure.or.kr |
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.