Korea tax guide
How to Convert Foreign Income to KRW for Korean Tax
Income Tax
Who this guide is for
- Foreign residents paid salary or freelance income in another currency
- Remote workers receiving overseas payroll
- Taxpayers with foreign interest, dividends, rent, or capital transactions
- People claiming a Korean foreign tax credit
Quick Answer
Korean tax returns are reported in won, so foreign-currency income must be converted using the rule that applies to that income and transaction date. The NTS explains that foreign income is generally reported in KRW using the exchange rate in effect when the income is received, while salary guidance can distinguish the actual payment date from an agreed payment date. Use a transaction-level schedule, one documented official rate source, and the same logic for related tax and basis records.
Key points
- Bank conversion date and taxable receipt date are not always the same.
- Different income types can have different recognition and conversion rules.
- Salary paid before or after an agreed payday can require a specific date analysis.
- A yearly average rate should not be used merely because it is convenient.
- Keep the rate source, date, currency, and calculation with every material transaction.
Step-by-step explanation
Start with the taxable event, not the bank exchange
For each item, identify when the income was earned, became payable, was actually paid, and was received or made available. Then apply the date rule for that income category. Exchanging USD, EUR, or another currency into won weeks later is a cash-management event and may not be the tax conversion date.
Build a transaction-level schedule
Use columns for payer, income category, foreign amount, currency, agreed date, actual payment date, tax-recognition date, rate source, rate, KRW amount, foreign tax, and supporting file. A transparent schedule is easier to defend and correct than a single annual total.
Treat salary timing carefully
NTS foreign-employee guidance distinguishes foreign-currency salary paid and converted before the agreed date from salary paid on or after that date. If payroll was delayed, advanced, netted, or paid through a foreign parent, retain the contract and payroll calendar and ask the employer which date and rate it used.
Use one authoritative rate source consistently
Save the source name, URL or downloaded table, date, and whether the rate is a standard or arbitrated rate. Do not mix a card-company rate, retail cash rate, bank transfer rate, and spreadsheet average without an explanation.
Reconcile income, basis, and credits
Foreign income, asset cost, sale proceeds, and foreign tax can use different relevant dates. Review the entire transaction chain so a currency gain, investment basis, or foreign tax credit is not calculated from incompatible conversions.
Documents you may need
- Foreign payslips and payment schedules
- Contracts stating agreed payment dates
- Bank and platform statements
- Dividend, interest, rental, and sale statements
- Exchange-rate source screenshots or downloads
- Foreign tax assessments and payment receipts
- KRW conversion spreadsheet with formulas
Common mistakes
- Using the day money was later exchanged at the bank for every item
- Applying one year-end rate to all income without authority
- Converting gross income and foreign tax with inconsistent dates
- Ignoring time-zone and settlement-date differences
- Keeping a final KRW total without the transaction-level calculation
When should you ask a tax professional?
Ask a qualified tax professional if you have income from several countries, business income, unclear tax residency, treaty questions, missing documents, late filing concerns, or a visa situation that depends on tax records. This site explains general patterns only and cannot review your personal facts.
FAQ
Can I use the annual average exchange rate?
Do not assume so. The NTS guidance points to an exchange rate tied to the relevant receipt or payment date for common foreign-income situations.
What if my foreign salary was paid late?
Salary guidance can distinguish payment before the agreed date from payment on or after it. Keep the employment agreement and actual payment record.
Should I use my bank's cash exchange rate?
The tax rule may refer to a standard or arbitrated rate under the foreign-exchange framework rather than a retail cash rate. Document the chosen official source.
How do I convert foreign tax for a foreign tax credit?
The conversion date for the foreign tax can differ from the income conversion date. Match the current foreign-tax-credit rule and retain proof of payment.
Official Sources to Verify
Tax rules and filing procedures in Korea may change depending on your visa status, income type, tax residency, and the tax year. Before making a tax decision, always verify your situation with official sources or a qualified professional.