2026 Comprehensive Income Tax Guide for Expats in Korea (May Tax Season)

If you earn income in South Korea, May is a critical month. It is the official filing period for the Comprehensive Income Tax Return (Jong-hap So-deuk-se, 종합소득세).

Unlike the Year-End Tax Settlement (Yeon-mal Jeong-san) which is handled by employers for regular workers in February, the May reporting period is for everyone else: freelancers, business owners, investors, and those with multiple income sources.

For expats and foreigners, this process can be daunting due to language barriers and complex tax laws. This guide will walk you through everything you need to know to file correctly and maximize your refund using our Income Tax Calculator.

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📋 Table of Contents

1. What is Comprehensive Income Tax?
2. Who Needs to File in May?
3. Key Dates & Deadlines (2026)
4. Tax Rates & Brackets
5. Deductions Available to Foreigners
6. How to File (Hometax Guide)
7. Penalties for Non-Filing
8. Frequently Asked Questions

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🏛️ What is Comprehensive Income Tax?

Comprehensive Income Tax is a tax levied on the sum of an individual’s income from various sources over a one-year period (January 1 to December 31).

Income sources subject to this tax include:

1. Business Income: Freelance income (3.3%), self-employment, rental income.
2. Wage & Salary Income: If you have multiple jobs or wasn’t settled in Feb.
3. Pension Income: Private pension withdrawals.
4. Interest & Dividend Income: If exceeding ₩20 million.
5. Other Income: Prizes, royalties, lecture fees, etc.

If you have any of these combined incomes exceeding certain thresholds, you must file a return in May.

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🙋‍♂️ Who Needs to File in May?

You MUST file if you fall into any of these categories:

1. Freelancers & Contractors: If you received payments with 3.3% tax deducted (e.g., English teachers, translators, developers). The 3.3% was just a prepayment; the May filing determines your actual final tax liability.
2. Business Owners: Sole proprietorships (Gae-in Sa-eob-ja).
3. Multiple Jobs: If you had two or more employers and didn’t combine them during the February settlement.
4. Missed February Settlement: If you left your job mid-year or forgot to submit documents for the Year-End Settlement.
5. Rental Income Earners: Landlords receiving rent (above specific limits).
6. Financial Income Earners: Aggregate interest/dividend income over ₩20 million.

Who does NOT need to file?

• Regular employees with only salary income whose company successfully completed the Year-End Settlement in February.
• Those whose only income is severed pay or retirement income (taxed separately).

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📅 Key Dates & Deadlines (2026)

• Filing Period: May 1, 2026 – May 31, 2026.
• Payment Deadline: May 31, 2026.
• Refund Payout: Usually late June to early July.

Important: If you miss the May deadline, you can file a “Post-Deadline Return” (Gi-han-hu Shin-go), but you may face penalties or reduced deductions.

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📉 Tax Rates & Brackets (2026)

Your tax is calculated based on your Refined Taxable Income (Gwa-se Pyo-jun), which is Total Income - Expenses - Deductions.

Taxable Income Range	Tax Rate	Deductions (Progressive)
Up to ₩14,000,000	6%	-
₩14M ~ ₩50,000,000	15%	₩1.26M
₩50M ~ ₩88,000,000	24%	₩5.76M
₩88M ~ ₩150,000,000	35%	₩15.44M
₩150M ~ ₩300,000,000	38%	₩19.94M
₩300M ~ ₩500,000,000	40%	₩25.94M
Over ₩1 Billion	45%	₩65.94M

• Local Income Tax: Add 10% of the calculated income tax.

🧮 Check Your Tax: Use our Income Tax Calculator to estimate your liability.

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💸 Deductions Available to Foreigners

Foreign residents are generally eligible for the same deductions as Korean citizens, with a few exceptions regarding housing and family dependents living abroad.

1. Basic Deduction

• Personal: ₩1.5 million per person.
• Dependents: ₩1.5 million for eligible spouse/parents/children (must meet income and age criteria).

2. Credit Card / Cash Receipt Deduction

• Eligible if total spending exceeds 25% of gross income.
• Important: You must have issued “Cash Receipts” (Hyeon-geum Yeong-su-jeung) using your phone number or ARC for cash purchases.

3. Pension Contributions

• National Pension: Fully deductible.
• Personal Pension Savings: Up to 16.5% tax credit on contributions (limit ₩6M~9M). This is the most powerful tax-saving tool.

4. Specialized Deductions for Expats

• Flat Tax Rate (19%): Foreign workers can choose a flat 19% tax rate on gross income instead of the progressive rate. This is beneficial strictly for high earners (typically annual salary > ₩140M).
• Housing: Monthly rent deduction is available for foreigners who meet specific visa/income requirements (check current year laws as this changes frequently).

5. Tax Treaty Benefits (Exemptions)

If you are from a country with a tax treaty with Korea (e.g., USA, UK, Canada, Australia), you might be exempt from Korean income tax for the first 2 years of employment, usually in education or research (e.g., University Professors, Teachers).

• Requirement: You must have submitted an “Application for Non-Taxation/Exemption” to your employer prior to receiving income.
• Warning: If you missed this filing, you cannot claim it retrospectively in May easily. You must file a correction request.
• Universities vs. Hagwons: Most public school and university jobs qualify. Private academies (Hagwons) usually do not qualify for tax treaty exemptions under the “Teachers” clause.

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💻 How to File (Hometax Guide)

You can file online via the National Tax Service’s Hometax (hometax.go.kr) or visit a local tax office (Se-mu-seo).

Step 1: Login

You need a “Joint Certificate” (Gong-dong In-jeung-seo) or “mSign” to log in.

Step 2: Select ‘Comprehensive Income Tax Reporting’

Navigate to Declaration/Reporting > Comprehensive Income Tax.

Step 3: Choose Reporting Type

The type of reporting depends on your income level and industry code. Hometax will usually assign this automatically, but knowing your type helps:

• S, A, B, C Types: These are for high earners who must keep “Double-entry Bookkeeping” (Bok-shik Bu-gi). If you fall here, you likely need a tax accountant.
• D Type: The “Standard Expense Rate” applies. You can calculate expenses as a percentage of revenue, but for income above a certain threshold, you must provide proof.
• E, F, G Types (Simple Expense Rate): For freelancers with lower income (usually under ₩24 million/year). The government assumes a very high expense rate (e.g., 60-70%), making your taxable income very low. Most part-time freelancers fall here.
• V Type: Taxpayers with financial income (interest/dividend) exceeding ₩20 million.

Pro Tip: If you are a G-type (Simple Expense Rate), Hometax often offers a “One-Click Filing” service (Modu-Chaem). You literally just click “Submit” if the data looks correct.

Step 4: Verify Income & Expenses

Hometax automatically pulls data for:

• 3.3% income reported by your clients.
• Credit card usage & Cash receipts.
• Pension & Insurance payments.

Critical: If you had business expenses (laptop, software, home office) not captured automatically, you must manually add them to lower your taxable income.

Step 5: Submit & Pay (or Refund)

• Outcome A (Refund): If your pre-paid 3.3% tax > calculated tax, you enter your bank account number to receive the difference.
• Outcome B (Payment): If you owe tax, you will get a virtual account number to transfer the balance.

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⚠️ Penalties for Non-Filing

Ignoring the May tax season is risky.

1. Non-Reporting Penalty: 20% of the unpaid tax amount.
2. Under-Reporting Penalty: 10% of the unpaid tax amount.
3. Late Payment Interest: ~0.022% per day of delay.

If you are a visa holder (E-7, F-2, etc.), tax delinquency can strictly prevent visa renewals or change of status (e.g., F-2-7 points require tax proof).

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❓ Frequently Asked Questions

Q1: I am an English teacher (E-2). Do I file?

If you are employed by a school (Hagwon/Public) and they finished your Year-End Settlement in Feb, no. But if you did private tutoring, worked part-time, or changed jobs mid-year without settling, YES.

Q2: How do I know if I have a refund?

In late April/early May, the NTS sends a “Tax Filing Notice” (KakaoTalk or mail). It often states your “Estimated Tax Amount”. A negative number (e.g., -200,000) means a refund!

Q3: Can I file expenses without receipts?

For low income earners, the government allows a “Standard Expense Rate” (e.g., assuming 60% of income is expense) without receipts. For high earners, you MUST have proof (Cash Receipts/Tax Invoices) for every expense.

Q4: Does the F-2-7 visa income requirement count ‘Before’ or ‘After’ tax?

Visa points are based on Gross Income (Before Tax) as listed on your “Income Amount Certificate” (So-deuk Geum-aek Jeung-myeong-seo). Filing your taxes correctly ensures this document reflects your true high income.

Q5: I forgot to file last year. What now?

You can file a “Retrospective Return” (Gi-han-hu Shin-go) on Hometax up to 5 years later. Do it ASAP to minimize interest penalties.

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🚀 Tools to Help You Prepare

Don’t guess your taxes. Use our specialized calculators to plan ahead:

Disclaimer: This guide is for informational purposes only. Korean tax laws are complex and subject to change. For specific advice, consult a certified tax accountant (Se-mu-sa).