If you worked at a small factory, a restaurant, or another small or mid-sized company in Korea, your employer may have taken too much income tax from you. The most common reason is a missed tax break: the SME youth reduction, a family deduction, or the rent credit. You can still get that money back for up to 5 past years with a correction claim (경정청구). You can file it yourself on Hometax.
Check the deadline first. In late 2026, income from 2021 is still claimable, but only until March 10, 2027.
Who can file a correction claim?
You can file if your income tax was settled at year-end settlement (연말정산), your employer filed your payment statement (지급명세서), and the tax settled was more than the law requires. The law also covers the case where your credits were less than the law allows.
The claim is measured against your withholding receipt (근로소득 원천징수영수증). If you only have wage income, you do not have to file a May income tax return, so the claim runs off your year-end settlement.
There are two limits to check first:
- Non-residents for tax. If you were a non-resident (비거주자) in the claim year, you cannot use this route yourself. The exceptions are when your employer has gone bankrupt or closed, or when you asked your employer for a good reason and it did not act. If you have since left Korea, ask the tax office whether you can still file for a year you lived here.
- Missing payment statement. If your employer never filed your payment statement, Hometax shows a message that you are not eligible for the wage correction claim. It tells you to check with your company. Ask your employer to file it first.
How long do you have? The 5-year window
The window is 5 years from the deadline for paying the year-end settlement tax.
Your employer runs year-end settlement on your February pay of the following year. Withheld tax is due by the 10th of the next month. So the tax for income year 2021 was due on March 10, 2022, and the claim window closes 5 years later.
| Income year | Last day to claim |
|---|---|
| 2021 | March 10, 2027 |
| 2022 | March 10, 2028 |
NTS says the 2025-income wage correction claim service opens around July 2026.
The SME employee income tax reduction
The SME employee income tax reduction (중소기업 취업자 소득세 감면) is the largest missed item for young workers at small and mid-sized companies. For youth, it cuts the income tax on that company's pay by 90%.
Who qualifies?
- Age. You were 15 to 34 on the day you signed the employment contract. That makes you "youth" under the law, with the 90% rate. People 60 or older, people with disabilities, and career-break workers get 70%.
- Hiring date. You joined the company between January 1, 2012 and December 31, 2026. For people 60 or older and people with disabilities, the start date is January 1, 2014.
- Employer. The company is a small or mid-sized company (중소기업) whose main business is on the legal list. The list includes agriculture, forestry, and fishing; mining; manufacturing (제조업); construction; wholesale and retail; transport and warehousing; and accommodation and restaurants. Bars and non-alcoholic beverage shops are not included. Ask your payroll team whether your company is on the list.
- Not excluded. Executives, the largest shareholder and their family, and daily workers (일용근로자) cannot get it. People whose national pension or employee health insurance payments cannot be confirmed are also excluded, unless they were not covered by national pension or health insurance in the first place.
How much is it?
| Income year | Rate (youth) | Yearly cap |
|---|---|---|
| 2018 to 2022 | 90% | ₩1.5 million |
| 2023 onward | 90% | ₩2 million |
For youth, the reduction covers pay up to the month that is 5 years after the hiring date (3 years for the other groups). The 5 years count from the first hiring date when you got the reduction. Moving to another qualifying company does not restart the count.
When the reduction applies, your earned income tax credit (근로소득세액공제) is scaled down at the same time. That is why the refund is a little less than 90% of your tax.
Does it apply to foreign workers?
Yes. Neither the law (Article 30) nor its decree (Article 27) has a nationality condition. NTS answers "네. 가능합니다." (Yes, it is possible) to a foreign worker who does not pay national pension because a social security agreement (사회보장협정) exempts them.
If you are not sure whether your national pension situation counts, ask the National Pension Service (국민연금공단, NPS). Which home countries are exempt is an NPS question, not a tax office question.
What it looks like in won
Here is a simplified example for 2024 income: total pay ₩30,000,000, hired at age 25 by a qualifying company, single, no rent credit. It ignores pension and health insurance premiums, so your own receipt will differ.
| Step | Amount |
|---|---|
| Earned income deduction | ₩9,750,000 |
| Taxable income after your ₩1,500,000 basic deduction | ₩18,750,000 |
| Calculated tax | ₩1,552,500 |
| Tax settled without the reduction (after the ₩740,000 earned income credit and ₩130,000 standard credit) | ₩682,500 |
| SME reduction (90%, under the ₩2 million cap) | ₩1,397,250 |
| Earned income credit after scale-down | ₩74,000 |
| Tax after the reduction | ₩0 |
| Refund for that year | ₩682,500 |
In this example the reduction brings the whole year's income tax to ₩0. If each of 5 open years looked like this one, the total would be roughly ₩3.4 million.
How to claim it for a past year
NTS says you can claim the reduction retroactively through a correction claim. Attach:
- A copy of the reduction application (중소기업 취업자 소득세 감면신청서).
- A copy of the reduction statement (감면명세서).
If you still work at the company, the normal route is to give the application to your employer. For new hires, it is due by the end of the month after the month you were hired. If you have left the company, file the application and the correction claim with the tax office for your home address (주소지 관할 세무서). If the company has closed, apply at that same office.
If you are changing jobs, the reduction can follow you to another qualifying company for the rest of your 5 years. Seoulstart Jobs lists Korea jobs for English speakers, including roles at small and mid-sized employers.
Missed dependents, including family abroad
Each eligible person gives you a basic deduction (기본공제) of ₩1.5 million from your taxable income. You count yourself, plus:
- Spouse with yearly income of ₩1 million or less (or only wage income with total pay of ₩5 million or less).
- Parents and grandparents aged 60 or older.
- Children aged 20 or under.
- Brothers and sisters aged 20 or under, or 60 or older.
Dependents need yearly income of ₩1 million or less (or only wage income with total pay of ₩5 million or less). Status is judged on December 31. Parents who live apart from you because of housing circumstances still count as living with you.
Family in your home country
NTS confirmed on January 7, 2026 that resident foreign workers can claim family who live abroad:
- Spouse abroad: yearly income of ₩1 million or less. Proof examples: family relation certificate, marriage certificate, and income certificate.
- Parents or children abroad: you need proof that you actually support them, such as records of money you send home for living costs.
We cover the rest of the deduction rules in the year-end tax settlement guide.
The monthly rent credit
If you rented on monthly rent (월세) and did not claim the credit, a correction claim can recover it. The current rules:
| Your total pay (and other income test) | Credit |
|---|---|
| ₩55 million or less (comprehensive income ₩45 million or less) | 17% of rent |
| ₩80 million or less (comprehensive income ₩70 million or less) | 15% of rent |
Rent above ₩10 million a year does not count. The home must be within national housing size (85㎡) or have an official price of ₩400 million or less. Officetels and goshiwon used as homes are included.
As a foreign resident you must be a registered foreigner, or an F-4 holder who reported a domestic residence. The address on your lease must match your registered stay address or reported residence.
The rules were less generous in earlier years. The 15% and 17% rates apply to settlements from January 1, 2023 (before, 10% and 12%). The ₩80 million pay limit applies from tax years starting January 1, 2024 (before, ₩70 million). Ask the tax office for the figures for an older year. Full rules: rent tax credit guide.
If you chose the 19% flat rate
Foreign workers who first started working in Korea by December 31, 2026 can choose to pay 19% of wage income as income tax. This covers tax years ending within 20 years of the first day of work in Korea.
A year under the flat rate gets no deductions, reductions, or credits. The SME reduction, family deductions, and the rent credit do not apply to that year. You choose the flat rate by attaching an application at year-end settlement or the May return. Once monthly withholding at 19% starts, stopping it takes effect only from the tax year after you file a withdrawal.
Ask the tax office before you file a correction claim for a flat-rate year. Background: 19% flat tax election guide.
How to file it yourself on Hometax
What to collect first
- Your withholding receipt for each year (download it from Hometax).
- Your employment contract, to show your age on the signing date.
- Your company's industry and SME status (ask payroll).
- Copies of the SME reduction application and reduction statement, if you claim the reduction.
- Family documents and records of money you send home, if you add dependents.
- Your lease and proof of rent payments, if you claim the rent credit.
The steps
- Log in to Hometax. At the time of writing, an NTS Hometax FAQ shows the path as Comprehensive Income Tax (종합소득세) → Wage earner filing (근로소득자 신고) → Correction claim (경정청구). Menu names change, so search for 경정청구 if you cannot find it.
- Pick the year. The same FAQ describes choosing the year in the year selection box (근로소득 경정청구 대상연도 선택) and clicking Search (조회).
- Read the year's manual. The claim screen has a help link (이용안내 도움말) with a manual for each claimable year.
- Fill in the claim. The form asks for your name and address, the tax base and tax before and after the correction, and the reason for the claim.
- Attach documents and submit.
What happens next
The tax office must decide, or tell you there is no reason to correct, within 2 months of receiving your claim. If you hear nothing in 2 months, you can start an objection or appeal from the next day.
File yourself, or pay a refund agent?
For the items in this guide, the work is collecting documents and entering numbers. If you file yourself, you keep the whole refund.
A paid refund agent or app charges a fee. Before you sign, ask for the fee in won for your own claim. Check it against your estimate from the tax refund estimator.
Help in your language
- English: the NTS help line for foreigners, 1588-0560. Weekdays 9:00 to 18:00, except 11:30 to 13:00.
- Other languages: call the Immigration Contact Center (1345), choose your language, and ask for a three-way call with the NTS consultation center (126).
- Written help: NTS publishes a year-end settlement booklet in English and explainers in English, Chinese, and Vietnamese.
- In person: the tax office for your home address, especially if you have left the company or it has closed.
FAQ
How many years back can I claim?
Up to 5 years from the deadline for paying the year-end settlement tax (March 10 of the next year). In late 2026, 2021 to 2025 are open, and 2021 closes on March 10, 2027.
Can a foreign worker get the SME youth reduction?
Yes, if you meet the age, employer, and payment conditions. The law has no nationality condition.
Is it too late if I missed the reduction at year-end settlement?
No, as long as the year is inside the 5-year window. File a correction claim with copies of the reduction application and statement.
Can I claim family who live abroad?
Yes. A spouse abroad needs yearly income of ₩1 million or less. Parents or children abroad need proof that you support them, such as remittance records.
Can I undo the 19% flat rate for a past year?
Ask the tax office before you file a correction claim for a flat-rate year.
How long does the refund take?
The tax office must decide within 2 months of receiving your claim. If you hear nothing in 2 months, you can start an objection or appeal from the next day.
Does the claim also refund local income tax?
Ask the tax office when you file.