The 3.3% withheld from many Korean freelance business-income payments is not your final tax. It is a prepayment. Your actual tax liability is calculated in May. If the prepaid withholding is larger than the final tax after deductions, credits, and other income are applied, the difference comes back as a refund.
If you have been doing freelance work in Korea and not filing in May, you are leaving real money at the National Tax Service (NTS). This guide explains exactly how the refund works, how to calculate it, and how to file.
All figures are current as of May 2026. Note: the standard filing deadline is May 31 each year. For 2026, the deadline is June 1 because May 31 falls on a Sunday. Verify the current-year deadline at hometax.go.kr before you file.
Who Can Claim the 3.3% Freelance Refund?
This guide covers foreign residents who:
- Received Korean freelance business-income payments with 3.3% withheld by a withholding agent
- Were Korean tax residents through a Korean domicile/address or 183 or more days of residence in the tax year
- Have not yet filed comprehensive income tax (종합소득세) for those years
What counts as freelance income here
Korean withholding agents generally withhold 3.3% when they pay personal-service business income such as:
- Freelancers (프리랜서): writers, designers, developers, translators, photographers, tutors
- Gig and platform workers: delivery, ride-share, on-demand services
- Independent instructors and coaches
- Anyone registered as a sole trader or issued a payment on business income (사업소득) rather than employment income
If your invoice payment came with 3.3% deducted at source, this guide is for you.
Visa type does not matter
The refund calculation is based on tax status and the final tax calculation, not your visa code. Your visa type does not decide whether prepaid 3.3% withholding is refunded.
Non-residents file differently
If you do not have a Korean domicile/address under the tax rules and spent fewer than 183 days in Korea in the tax year, you may be a non-resident (비거주자) for tax purposes. Non-residents have different filing rules and different rates. If you are unsure of your residency status, consult a 세무사 before filing.
How Is the 3.3% Freelance Refund Calculated?
This is the mechanic that determines whether withholding turns into a refund or additional tax.
Step 1: Withholding is collected at a flat rate
Your Korean withholding agent withholds 3.3% from each personal-service business-income payment. At the end of the year, suppose your total freelance income was ₩30,000,000. Total withholding: ₩30,000,000 x 0.033 = ₩990,000 sitting at the NTS.
Step 2: The simplified expense ratio (단순경비율) reduces your taxable income
When you file in May, eligible filers can deduct a portion of gross income as deemed business expenses. The rate depends on your business code (업종 코드), and the NTS sets different rates by code and income year. Do not borrow another freelancer's rate.
The worked examples below use NTS's 1-person media creator example code, 940306, which lists a 64.1% simplified expense rate and a 49.7% excess rate. Your own code may be different. Look up your exact code and rate at the NTS expense ratio lookup table before filing.
Step 3: Apply the basic personal deduction
All individual tax filers get a basic deduction (기본공제) of ₩1,500,000 per person. Additional deductions apply for dependents, disability status, and other circumstances.
Worked example: ₩30 million freelance income
Assume: foreign freelancer, content writer (business code 940306), ₩30,000,000 gross freelance income, no other income, single filer.
| Step | Calculation | Amount |
|---|---|---|
| Gross income | ₩30,000,000 | |
| Simplified expense deduction (64.1%) | ₩30,000,000 x 0.641 | -₩19,230,000 |
| Income after expenses | ₩10,770,000 | |
| Basic personal deduction | -₩1,500,000 | |
| Taxable income | ₩9,270,000 | |
| Tax at 6% bracket (up to ₩14M) | ₩9,270,000 x 0.06 | ₩556,200 |
| Local income tax (10% of national) | ₩556,200 x 0.10 | ₩55,620 |
| Total actual tax owed | ₩611,820 | |
| Amount already withheld (3.3%) | ₩990,000 | |
| Refund | ₩990,000 - ₩611,820 | ₩378,180 |
Now the same freelancer at ₩20,000,000:
| Step | Calculation | Amount |
|---|---|---|
| Gross income | ₩20,000,000 | |
| Simplified expense deduction (64.1%) | ₩20,000,000 x 0.641 | -₩12,820,000 |
| Income after expenses | ₩7,180,000 | |
| Basic personal deduction | -₩1,500,000 | |
| Taxable income | ₩5,680,000 | |
| Tax at 6% bracket | ₩5,680,000 x 0.06 | ₩340,800 |
| Local income tax | ₩340,800 x 0.10 | ₩34,080 |
| Total actual tax owed | ₩374,880 | |
| Amount already withheld (3.3%) | ₩660,000 | |
| Refund | ₩660,000 - ₩374,880 | ₩285,120 |
At ₩15,000,000 gross income with the same rates:
| Step | Calculation | Amount |
|---|---|---|
| Gross income | ₩15,000,000 | |
| Simplified expense deduction (64.1%) | ₩15,000,000 x 0.641 | -₩9,615,000 |
| Income after expenses | ₩5,385,000 | |
| Basic personal deduction | -₩1,500,000 | |
| Taxable income | ₩3,885,000 | |
| Tax at 6% bracket | ₩3,885,000 x 0.06 | ₩233,100 |
| Local income tax | ₩233,100 x 0.10 | ₩23,310 |
| Total actual tax owed | ₩256,410 | |
| Amount already withheld (3.3%) | ₩495,000 | |
| Refund | ₩495,000 - ₩256,410 | ₩238,590 |
These examples use the 64.1% rate for business code 940306 and show tax before standard tax credits. Your rate depends on your specific business code and income year. Actual tax owed may be lower, and refunds may be larger.
Why a refund is common
Korea's progressive tax brackets tax people more as income rises. The 3.3% flat withholding is a rough prepayment. For some lower-income filers, withholding can exceed actual progressive-bracket liability after the expense ratio, deductions, and credits are applied.
When Must I File for the 3.3% Refund?
The comprehensive income tax (종합소득세) filing window is May 1 to May 31 each year, covering the prior calendar year's income. For 2026 specifically, the deadline is June 1, 2026 because May 31 falls on a Sunday (as of 2026, verify at hometax.go.kr).
File for:
- 2025 income: file May 1 to June 1, 2026
- 2024 income (if you missed it): file a late return (기한후신고) now
- 2023, 2022, 2021 income: late returns still open under the 5-year window
Documents you need before filing
Gather these before you open Hometax:
Required:
- Foreign registration card (외국인등록증) number. This is your Hometax login ID.
- Withholding receipts (원천징수영수증) from each client. These are usually pre-loaded in Hometax because clients file payment statements (지급명세서) with the NTS. Pull them from Hometax under "Payment Statement Inquiry" before you start.
- Korean bank account number for the refund deposit
If you want to claim actual expenses (기준경비율 method, see below):
- Tax invoices (세금계산서) and card receipts for major business expenses (equipment, software, workspace, subcontractor fees)
- Expense receipts totalled and categorized
Optional but helpful:
- A summary of all client payments received during the year: dates, amounts, payers. Cross-check this against what Hometax shows as pre-loaded.
Three ways to file
Option 1: Hometax (PC, free)
hometax.go.kr is the NTS's main web portal. The interface is Korean-only. For a straightforward single-source freelance return, the filing wizard pre-fills income data from client payment statements. Your steps:
- Log in with your foreign registration number (외국인등록번호) and register for an ID if it is your first time.
- Go to: Report/Payment (신고/납부) > Comprehensive Income Tax (종합소득세) > File Return (신고하기).
- Select the simplified return (단순경비율 신고) if your income is within the threshold for your business code. For human-services freelancers (업종코드 94*), the simplified expense ratio applies if your prior-year gross income was below ₩36,000,000 (as of 2026, confirm in the wizard; the ₩75,000,000 figure you may see elsewhere is the separate bookkeeping obligation threshold). Verify your specific code and threshold at the NTS expense ratio eligibility page.
- The system pulls in client payment data automatically. Verify the amounts against your own records.
- Confirm the expense ratio applied and the deductions. Review the calculated refund or tax owed.
- Enter your Korean bank account for the refund and submit.
Processing time: income-tax refunds after regular May filing are commonly around late June to early July, and local income tax can follow later.
Option 2: Son-Tax (손택스) mobile app, free
Son-Tax (손택스) is the NTS mobile app available on iOS and Android. It supports 종합소득세 filing. Download from the App Store or Google Play and log in with your foreign registration number.
Option 3: Hire a 세무사 (tax accountant)
A licensed tax accountant (세무사) will handle the full filing for you. Consider one if:
- You have both employment income and freelance income
- You have income from multiple countries
- You are unsure whether 단순경비율 or 기준경비율 applies to your business code
- You are filing late returns or corrections for multiple past years
Find a 세무사 through the Korean Tax Accountants Association directory at kacpta.or.kr. Ask in advance about language support, filing scope, and price.
Should I Use the Simplified or Standard Expense Ratio?
Most foreign freelancers use the simplified expense ratio (단순경비율). Here is how to know which applies to you.
Simplified expense ratio (단순경비율)
Use this if your prior-year freelance gross income was below the threshold for your business code. For human-services freelancers (인적용역, business code 94*), the threshold is ₩36,000,000 prior-year income (as of 2026, verify at the NTS expense ratio eligibility page). Note: the ₩75,000,000 figure mentioned in some guides is the separate bookkeeping obligation (복식부기) threshold, a different test. Benefits of 단순경비율: no receipts required, straightforward filing, high deduction percentage.
Standard expense ratio (기준경비율)
Required if your gross income exceeds the 단순경비율 threshold for your code. Under this method, you deduct actual receipted expenses (called major expenses: rent, payroll, purchase costs) plus a smaller government-set rate for other expenses. You need to keep and submit receipts for major items. The effective total deduction is usually lower than 단순경비율, but actual high-cost expenses can be fully claimed.
If you cross from 단순경비율 to 기준경비율 territory mid-career, the difference in filing complexity is significant. This is the main reason to hire a 세무사 when income grows above the threshold.
Common traps
Missing the May 31 deadline
Filing late can trigger a late-filing surcharge (무신고가산세): 20% of the unpaid tax in ordinary non-filing cases. If your actual unpaid tax is zero, that penalty base may also be zero, but late filing still delays or complicates the refund. File on time to protect your refund.
Late returns (기한후신고) for past years can still be filed within the 5-year window regardless of the current-year deadline.
Filing as a non-resident when you are actually a resident
If you had a Korean domicile/address under the tax rules or were in Korea for 183 or more days in the tax year, you are a tax resident and should file as 거주자 using the resident rules. Filing as a non-resident (비거주자) when you are actually a resident is an error. If Hometax asks for clarification, count your days and facts carefully.
Taking the wrong 단순경비율 rate
Every business code (업종 코드) has its own simplified expense ratio. Using the wrong rate, even if it is higher (which looks better for your refund), is an error the NTS can query. Look up your exact code at the NTS expense ratio table before filing.
Mixed employment and freelance income
If you have both a salaried job (processed through 연말정산) and freelance income, you must file 종합소득세 in May to declare the freelance income. The two types are combined and taxed together. Depending on your employment income level, the combined bracket can result in a lower refund or a small amount owed on the freelance income portion. A 세무사 is worth the fee here.
Flat-tax election on employment income does not block the freelance refund
Some foreign residents with employment income elect the 19% flat tax on employment income. That election applies to employment income, not to whether your personal-service business-income withholding is reconciled. You can still file the freelance business-income return; the final result depends on the full tax calculation.
If you have never filed: the 5-year late-return path
If you have been doing freelance work in Korea since 2021 and never filed 종합소득세, you can still recover withheld tax for 2021, 2022, 2023, 2024, and 2025.
The key distinction: a never-filer cannot use an amendment claim (경정청구, National Tax Basic Act Article 45-2) directly. That tool corrects a return that already exists. You must first file a late return (기한후신고) for each open year under Article 45-3. Once the late return is on file, you can then use 경정청구 if you need to correct it. Both steps can be completed through Hometax within the 5-year window from the original filing deadline.
How to calculate what you might be owed
Take your best estimate of annual gross freelance income for each missed year. Apply the 단순경비율 for your business code. Subtract ₩1,500,000 basic deduction. Run the bracket math. Subtract 3.3% already withheld. The remainder is your approximate refund for each year.
Using the simplified examples above, ₩20,000,000 per year over 5 years would be about ₩285,000 per year x 5 = ₩1,425,000 before other credits or adjustments. At ₩30,000,000 per year over 5 years, the same example logic gives about ₩378,000 per year x 5 = ₩1,890,000.
These are estimates. Your exact refund depends on your actual income, business code rate, and any other deductions you qualify for. The numbers are directionally correct for typical freelance income levels.
How to file a late return for a missed year
- Log into Hometax and go to: Report/Payment (신고/납부) > Comprehensive Income Tax (종합소득세) > Late Return (기한후신고).
- Select the tax year you are filing for (start with the oldest year still within 5 years).
- The system will load available payment statement data for that year. If a client filed properly, their payment to you and the withholding amount will appear automatically.
- File the simplified return for that year the same way you would file a current-year return.
- Repeat for each missed year.
- Income-tax refunds after late returns can take longer than regular May filing; timing varies by case and tax office.
Missing payment data: if a client did not file their payment statement (지급명세서), their payment to you may not appear in Hometax. In that case, you can enter the income manually and attach the withholding receipt (원천징수영수증) you received from the client at the time of payment. If you no longer have the receipt, contact the client and ask them to provide it.
What to do next
- Log into Hometax at hometax.go.kr using your foreign registration number. Pull the "Payment Statement Inquiry" (지급명세서 조회) to see what income and withholding data the NTS already has for you.
- Identify every year since you started freelancing in Korea that you have not yet filed for.
- Find your business code (업종 코드) and the corresponding 단순경비율 rate at the NTS expense ratio table. Run the rough calculation above to estimate the refund for each year.
- File the current year's return in May. For any missed past years, file a late return (기한후신고) through Hometax for each open year within the 5-year window.
- If your situation is complicated (mixed income types, multiple countries, or high income crossing into 기준경비율 territory), consider hiring a 세무사 who can file correctly the first time.
The money is already at the NTS under your registration number. Filing is the only step between you and the refund.
FAQ
Do I have to file comprehensive income tax (종합소득세) if I only did freelance work for a short time?
If you received Korean freelance business income with 3.3% withheld and were a Korean tax resident for that tax year, yes. There is no general minimum income threshold in this guide that lets you ignore reported business income. If your income was small, the refund may be small too, but filing keeps the record clean.
My Korean client says they did not withhold 3.3%. Is that normal?
It can happen in a few situations: the client may have paid you as employment income (in which case different withholding rates apply and you receive a 근로소득 원천징수영수증), the client may have failed to withhold when they were required to, or the arrangement may genuinely not be classified as freelance business income under the tax code. If 3.3% was not withheld, check what was withheld and what type of income was reported. Ask the client to provide a withholding receipt (원천징수영수증). Do not assume no withholding means no filing obligation. The filing requirement is based on the type of income, not whether the client withheld properly.
Can I claim home office and equipment expenses?
Under the simplified expense ratio (단순경비율), you do not claim individual expenses. The government rate covers deemed expenses. You can switch to the standard expense ratio (기준경비율) to claim actual expenses, but this requires receipts and is more complex. Compare the two methods before choosing.
Does the 3.3% refund affect my home country tax filing?
Possibly. The amount you receive as a refund from the NTS is not additional Korean income; it is the return of a prepayment. Talk to a tax professional familiar with your home country's rules before claiming any foreign tax credit abroad. The NTS withholding receipt (원천징수영수증) documents Korean tax withheld.
My Hometax data shows different income than what I was actually paid. What do I do?
Cross-check the Hometax payment statement data against your own records (bank statements, invoices, client payment confirmations). Discrepancies usually occur because: (1) a client filed the payment statement late or incorrectly, (2) a foreign-entity client is not required to file Korean payment statements, or (3) a client paid you under a different income category. You can manually enter income that does not appear in the pre-filled data, supported by your own withholding receipts. If you are uncertain, a 세무사 can help reconcile the discrepancy before you submit.
What happens if I just ignore the filing requirement?
The NTS may contact you or issue an assessment if clients have filed payment statements showing income under your registration number that was never reported on a return. Failure to file on income the NTS already knows about can result in a notice of additional tax plus surcharges. The downside risk grows with the size and number of years of unreported income. Filing is the correct action.