Missed a Deduction at Year-End Tax Settlement? Claim It Within 5 Years

The diagram below is a self-made illustration, not a real screen.

Forgot to submit a document during your year-end tax settlement? You don’t have to give up on it.
According to the National Tax Service (NTS), you can still add it later through the May income tax filing or a correction claim (경정청구).

Who this is for

• Employees who missed a deduction document at their company’s year-end settlement
• Anyone unsure whether they claimed dependents, rent or medical costs correctly
• Anyone who wants to review a settlement from past years

Step 1. What’s the deadline?

• May income tax filing period: the NTS says you can add missed deductions by filing a final income tax return then.
• After that, a correction claim: under Article 45-2 of the Framework Act on National Taxes, you can file within 5 years after the statutory filing deadline.
• For employees, the NTS gives the statutory deadline as May 31 of the following year.
• This applies when your employer paid the settled tax and filed the payment statement on time.

Step 2. Deductions worth rechecking (per the NTS)

These requirements come from an NTS press release (January 23, 2026). Check both ways: did you miss something, or claim something you weren’t eligible for?

• Basic deduction for dependents: ₩1.5M per person.
• The dependent’s annual income must be ₩1M or less, or a total salary of ₩5M or less if wages are their only income.

• Age rules: parents must be 60 or older and children 20 or younger. There is no age rule for dependents with a disability.

• Medical expenses: the NTS says medical costs you paid for a dependent are deductible even if that dependent is over the income limit.

• Glasses and contact lenses: up to ₩500,000 per person.

• Postnatal care centers: up to ₩2M per birth.

• Monthly rent tax credit: you must be a homeless head of household as of December 31, with a total salary of ₩80M or less.

• You must register your move-in and actually live there.

• The credit is 15–17%, on up to ₩10M of rent a year.

• If you couldn’t get the rent credit: the NTS says you can apply on Hometax for a rent cash receipt (after login) and claim it under the credit-card deduction instead.

• A spouse who died during the year: the NTS says the spouse deduction can still apply, based on the situation the day before the death.

Step 3. Filing on Hometax

This step happens after you log in to Hometax. After logging in, search for 경정청구 (correction claim) in Hometax to find the claim form. Menu names can change.

• Choose the tax year, fix the missed deduction, and submit the claim.
• Supporting documents are submitted separately. The NTS warns that if you don’t submit them, the change may not be applied properly.
• If your employer’s payment statement is wrong, you can’t fix it yourself. It has to be corrected through your employer.
• The auto-fill service isn’t available in some cases, for example if pay from two employers wasn’t combined, or if no refund results. In those cases, file on paper with your local tax office or use another filing method.

Common mistakes

• Forgetting to submit supporting documents
• Two spouses or siblings both claiming the same family member (only one person can)
• Claiming medical costs that insurance paid back (subtract the reimbursed amount)
• Trying to file after the 5-year window has closed

Checklist

• ☐ Is the tax year within the 5-year window?
• ☐ Do you have the documents for the missed deduction?
• ☐ Did you check the dependent’s income and age requirements?
• ☐ Has anyone else already claimed the same family member?
• ☐ Did you check whether your employer’s payment statement itself has an error?

For more questions, call the NTS counseling center at 126 (no area code).

For more money you may be missing, see our guide to finding hidden money.

We also have a $4.99 PDF guide that collects more everyday money-saving tips. Take a look if it’s useful →