Illustrative planning photograph; not an identified applicant, adviser or client.

Asking a Korea Tax Question: Identify the Income Period and Payer First

작성자:

Before you ask the National Tax Service (NTS) or an adviser a Korean tax question, write down three facts: who paid you, what kind of income it was, and which tax year it belongs to. Korea assesses personal income tax on a calendar year, from 1 January to 31 December, according to PwC’s Worldwide Tax Summaries, and the answer to almost every question depends on those three facts plus whether you count as a tax resident.

Fact 1: the tax year the payment belongs to

PwC states that personal income tax is assessed for one year from 1 January to 31 December, with the return filed from 1 May to 31 May of the following year and tax due by 31 May. A payment received in December and a payment received in January therefore fall in different tax years, even if they relate to the same project. Note the date you received the money and the period of work it covers, and keep the two apart.

Deadlines that fall on a weekend or holiday can move. A Busan city announcement on local income tax filing, for example, shows a filing period that ended on 2 June rather than 31 May for that year. Check the date for the year in question on the NTS site.

Fact 2: who paid you, and from where

PwC distinguishes two types of employment income. Class A income comes from Korean entities, or from foreign entities that charge the cost back to a Korean entity, and is subject to monthly payroll withholding. Class B income comes from foreign entities without a Korean tax deduction claim, and the individual declares and pays tax annually. Which class applies depends on the payer, so record the paying company’s name and country and whether it charges the cost to a Korean affiliate.

The NTS year-end settlement manual for foreigners explains that the employer or organisation paying wage and salary income acts as the withholding agent, calculating and remitting tax monthly. If someone other than an employer paid you, such as a client, write that down; the withholding position can be different.

Fact 3: the kind of income

PwC lists the recognised categories: employment income, interest income, dividend income, personal business income (including rental income), pension income and other income. The label used in a casual message, such as “bonus”, “fee” or “allowance”, does not decide the category. Keep the original contract, invoice or pay statement so that an adviser can see what the payment was for.

Fact 4: your residence status

PwC says an individual is a resident for Korean income tax if they have a domicile in Korea or reside in Korea for 183 days or more in a tax year, and it notes a new consecutive-period rule as of 2026 for residence of 183 days spanning two tax years. The NTS manual states that residents pay tax on worldwide income while non-residents pay on domestic-source income only. PwC adds that residence is judged on facts and circumstances, including family and property ties. Because the effect is so large, record your arrival and departure dates for each year and whether family members live with you in Korea.

PwC also notes that residents who have stayed longer than five years in the last ten must include foreign-source dividends and interest, while those who have stayed five years or less include foreign-source income only if it is paid by a Korean entity or transferred to Korea. Do not apply this yourself; mention your years of stay to the adviser or the NTS.

Who has to file a return

According to the NTS manual, foreign residents whose only income is wage and salary settled through the employer’s year-end settlement do not need to file an additional global income return, while others file in May of the following year. PwC adds that expatriates with only Class A salary or retirement income are not required to file before leaving Korea, but those with other types of income must file before departing. If you have freelance, rental, dividend or foreign-employer income in addition to a Korean salary, ask which return applies.

A fact sheet to prepare before you call or write

  1. Tax year: the calendar year of receipt.
  2. Payer: name, country, and whether a Korean entity bears the cost.
  3. Payment: amount, currency, date received and the period of work.
  4. Documents: contract, invoice, pay statement and any withholding receipt.
  5. Residence: dates in Korea, family and property in Korea.
  6. Your question in one sentence: for example, “Do I need to file for this income?”

Common mistakes and what to verify

  • Mixing tax years. Put each year’s documents in a separate folder.
  • Assuming the label decides the tax category. Keep the original document instead.
  • Assuming one rule for all foreigners. Resident and non-resident rules differ, and PwC says status depends on facts and circumstances.
  • Using an old guide. The NTS manual cited here is an older edition; PwC states some rules, such as the consecutive-period residence test, are new as of 2026.
  • Waiting until you leave. PwC says some expatriates must file before departing Korea.

Rules change: confirm with the official body

This article is general information and not tax, legal or financial advice. Tax rates, filing dates, residence tests and special elections are set by the National Tax Service and the Ministry of Economy and Finance and are amended regularly. Confirm your own position with the NTS or a qualified tax adviser before filing or paying, and use the NTS website for the current year’s forms and dates.

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