How to File Taxes in Korea as an Expat (2026 Guide)

Tax season in Korea can feel overwhelming when you're navigating it in a foreign language, dealing with unfamiliar systems, and wondering if you're leaving money on the table. The good news? Once you understand the system, you can minimize your tax burden, maximize deductions, and even get money back.

This guide breaks down everything expats need to know: who files when, how to navigate Hometax, which deductions you're missing, and common mistakes that cost you money.

Before diving into the mechanics, let's clarify what you're actually doing.

Year-End Tax Settlement (연말정산)

• For employees with a single employer
• Happens in January-February
• Your employer handles most of it
• You provide deduction documents, they adjust your tax liability
• Refund or payment appears in your February/March paycheck

Comprehensive Tax Filing (종합소득세 신고)

• For freelancers, side hustlers, multiple income sources
• Happens in May (deadline: May 31)
• You file it yourself via Hometax or in person at a tax office
• Covers all income from the previous year

Key difference: If you're a single-income employee, you're doing year-end settlement. If you earn freelance income, rental income, or have multiple jobs, you're filing comprehensive.

Korea uses a progressive tax system:

Plus: Local income tax = 10% of your national income tax (so effective rates are slightly higher).

• When: January–February
• What: Year-end tax settlement (연말정산)
• How: Your employer provides forms; you submit deduction documents

• When: May 1–31
• What: Comprehensive tax filing (종합소득세 신고)
• How: File online via Hometax or in person at tax office

• When: May 1–31
• What: Comprehensive tax filing (종합소득세 신고)
• Example: Teaching at a hagwon + freelance tutoring on the side

• If you left in January–April: Your former employer should handle year-end settlement.
• If you left May-December: You file comprehensive in May the following year.
• If your employer won't process your settlement, you file in May yourself

This is the big one for most expats. Here's how it works.

What you'll need:

• Kakao certificate (or bank certificate, Mobile ID, Naver, Toss)
• Your resident registration number (ARC number)

The Process:

1. Go to hometax.go.kr
2. Click the blue shortcut: 연말정산 간소화 (공제자료 조회/발급)
3. Enter your name and resident registration number
4. Agree to personal information use (check all boxes)
5. Login via 간편인증 로그인 (simple authentication)
   1. Choose Kakao, Naver, Toss, or bank certificate
6. If using Kakao:
   1. Enter name, birthday, phone number
   2. Click 인증 요청 (authentication request)
   3. You'll receive a Kakao message
   4. Click the yellow 인증하기 button in Kakao
   5. Verify with fingerprint/passcode
7. Back at Hometax, click 인증 완료 (authentication complete)
   1. You may wait in a queue (especially in late January)
8. Check two boxes at the bottom (personal info agreement)
9. Click 연말정산간소화 시작하기 (start year-end settlement)
10. Click each of the magnifying glasses (조회하기) to populate your data
    1. These pull your spending across 16 categories: medical, education, insurance, donations, etc.
11. Click 내려받기 (download) in the top right
12. Save as PDF: PDF로 내려받기
13. Give this PDF to your employer

Your employer's tax accountant:

• Takes your deduction document
• Adds employer-provided info (salary, national pension, health insurance)
• Calculates your final tax liability

• Refund: Appears in your February or March paycheck
• Owe money: Deducted from your February or March paycheck

Tip: If you owe a lot, it means you didn't have enough withheld during the year. Ask your employer to adjust monthly withholding.

Freelancers file in May for the previous year's income.

Throughout the year, keep records of:

• Income: Invoices, bank transfers, contracts
• Expenses: Receipts for work-related costs (office supplies, software, travel, etc.)
• Tax withheld: If clients withheld 3.3% tax, you get credit for that

Option 1: File Online (Hometax)
1. Go to hometax.go.kr
2. Login (same method as employees)
3. Navigate to 종합소득세 신고 (comprehensive income tax filing)
4. Follow the step-by-step wizard
5. Enter all income sources
6. Enter deductible expenses
7. System calculates tax owed or refund
8. Pay via bank transfer or receive refund

Option 2: In-Person Filing

1. Go to your local tax office (세무서)
2. Bring: ARC, income records, expense receipts, bank statements
3. Staff can help you fill out forms (limited English support)

If you're earning significant freelance income, you may need to make quarterly estimated tax payments to avoid penalties. Talk to a tax accountant if your annual freelance income exceeds 10 million KRW.

This is where you save money. The Hometax system automatically pulls some of these, but you need to know what qualifies.

How it works:

• Spending over 25% of your salary is deductible
• Credit cards: 15% deduction rate
• Debit cards / cash receipts: 30% deduction rate
• Traditional markets, public transport: 40% deduction rate

Tip: Use debit cards instead of credit cards. Higher deduction rate.

What counts:

• Groceries, restaurants, shopping, transportation
• Must be registered in your name (ARC-linked cards)

What doesn't count:

• Online shopping from overseas sites
• Cash without receipt
• Gift cards

What qualifies:

• Hospital visits, prescriptions, dental, vision
• Plastic surgery does NOT count
• Health insurance premiums are automatically deducted

Deduction rate: 15% of expenses over 3% of your salary

How to claim:

• Most automatically populate in Hometax
• For small clinics, ask for 영수증 (receipt) with your ARC

What qualifies:

• University tuition (for you or dependents)
• Kindergarten, elementary, middle, high school fees
• Korean language classes at accredited institutions
• Most Korean language classes at private academies don't qualify. University-affiliated programs do.

Deduction rate: Varies (tuition is often 15%).

What qualifies:

• National health insurance (자동 deducted)
• National pension (자동 deducted)
• Private insurance (must be Korean policies)

What qualifies:

• Donations to registered Korean charities
• Religious donations (churches, temples, mosques)

Deduction rate: 15-30% depending on organization

How to claim:

• Get official receipt (기부금 영수증)
• Must include your ARC number

Automatically deducted:

• National Pension (국민연금)

Additional option:

• Private pension plans (연금저축) offer tax benefits
• Up to 4 million KRW deductible (12-15% rate)

Jeonse loans:

• Interest on jeonse loans is partially deductible

Monthly rent:

• Up to 7.5 million KRW deductible (if income is under 70M and you don't own property)

What qualifies:

• Subway, bus (using T-money, Cashbee)
• Must be registered under your name

How to register:

• Link your T-money card to your ARC via the T-money app or at convenience stores

Deduction rate: 40%

Cash spending doesn't count unless you request a 현금영수증 (cash receipt). At stores, say "현금영수증 주세요" and provide your ARC number or phone number. Register your phone number for cash receipts via the Hometax app

You teach a few private students on the side, earn 5 million KRW. You don't report it. Years later, NTS audits you. All income is taxable. Even side gigs. File comprehensive in May if you have any freelance income.

Korean taxes are complicated, but they're not impossible. The key is staying organized, understanding which deductions apply to you, and filing correctly and on time.

Action steps:

1. Link all cards to your ARC
2. Request cash receipts for large purchases
3. Track medical, education, and donation expenses
4. File your deduction documents in January (employees) or comprehensive in May (freelancers)
5. If confused, ask for help. Better to pay an accountant than face penalties

Tax season doesn't have to be stressful. Do it right, and you might even get money back.