Declaring Your Income in France: How, When, Tips.

Start with JARI.

Filing your income tax in France as a Korean raises specific questions: your first return, income earned in Korea, the tax treaty, which boxes to tick, deadlines by department. A mistake can mean a penalty. JARI's Professional Services guide you through your return, check your tax-residency status, and help you avoid the traps. You file correctly, the first time.

Who has to file?

If you're a French tax resident (your home, main stay, or main activity is here), you declare your worldwide income, including income earned in Korea — the France-Korea tax treaty prevents double taxation. Even with no taxable income, filing is often useful (proof of income, housing benefit, scholarships…).

The 2026 calendar (2025 income).

• Online service opens: Thursday 9 April 2026.
• Paper return: by 19 May 2026 at the latest (including for residents abroad).
• Online deadlines, by department:
  • Departments 01 to 19 and non-residents: Thursday 21 May 2026
  • Departments 20 to 54: Thursday 28 May 2026
  • Departments 55 to 974/976: Thursday 4 June 2026 (11:59 pm)
• Online correction possible from mid-August to mid-December 2026.

How to file, step by step.

1. Log in to impots.gouv.fr with your tax number (or create your account using the credentials mailed to you).
2. Check the pre-filled return: salaries, pensions, withholding tax are often already shown. Correct if needed.
3. Add any missing income (foreign, rental, self-employed…).
4. Enter your tax reductions and credits (donations, childcare costs, home employment…).
5. Check your withholding rate and instalments.
6. Validate and keep the acknowledgment of receipt.

Your first return.

In your first year you don't always receive an automatic letter. You can file online as soon as you receive your credentials, or file a paper return (form 2042). Remember to report your change of address and family situation.

Income earned in Korea: the tax treaty.

The France-Korea tax treaty determines which country taxes what and applies a mechanism to avoid double taxation (tax credit or exemption depending on the type of income). Foreign income is declared on form 2047, then carried over to the 2042. This is the trickiest part — best to get it right.

Reductions and credits not to forget.

Donations to charities, childcare costs, employing someone at home, retirement savings contributions (PER)… these genuinely reduce your tax. Gather your supporting documents before filing.

After filing.

You receive a tax notice in the summer. If withholding didn't cover everything, a balance is collected in the autumn; if it took too much, you're refunded. Check and update your rate if your situation changes (marriage, birth, drop in income).

Get support.

Tax residency, the France-Korea treaty, specific boxes: a poorly filled return is costly. Have your return checked by JARI's Professional Services to file correctly, optimize your tax credits, and stay compliant.

Going further.

Understand the overall system with Understanding taxes in France, how withholding tax works, and the special case of the first return & tax residency.

Useful links.

• Déclarer en ligne — impots.gouv.fr
• service-public.fr — déclaration de revenus