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Comprehensive Income Tax (May)

Comprehensive income tax combines your various incomes from last year into one self-filing each May. If you only have a single wage income settled at year-end, you usually don’t file separately — but multiple jobs, freelance (business income), business, rental, or other income can make you liable. Long-term residents are generally treated as tax ‘residents,’ so Korea-source income may be filable. You file on Hometax (web) or Sontax (app), and the window is usually all of May (commonly through May 31).

Based on official sources · verify before deciding· as of 2026-06-09Official site ↗

How to proceed

  1. 1Check whether you must file (multiple jobs, freelance, business, rental, other income). Also read the NTS ‘filing guide’ notice sent in May
  2. 2Sign up / log in to Hometax (you can register with your ARC number) or get the Sontax app ready
  3. 3During May, complete and submit the return under ‘Comprehensive income tax filing’ on Hometax/Sontax
  4. 4Depending on the result, pay the tax or register your account for a refund (note the late-May deadline)
  5. 5If it’s hard, use a tax agent (accountant) or call NTS ☎126 (foreigners: English help ☎1588-0560)

Tips

  • ⚠️ Missing the May filing/payment deadline (commonly May 31) can bring penalty tax and other downsides — don’t delay; if you have a valid reason, ask Hometax/the tax office whether a deadline-extension applies (verify amounts/conditions officially).
  • If you earned wages from more than one company, year-end settlement alone may not finish it — a combined May filing may be needed.
  • Freelance income that had 3.3% (etc.) withheld (business income) is also filed in May, so you may owe more or get a refund (results vary by person).
  • Whether the flat-rate special applies and at what rate depends on your situation and the year — we don’t state figures here; confirm with NTS or a tax accountant.
  • If you have many income/deduction types and it’s complex, using a tax accountant is the safe route.

Key contacts

  • NTS Semirae call center ☎126
  • Foreigner English help line ☎1588-0560
  • Hometax hometax.go.kr · Sontax (mobile app)
  • If complex, consult a tax office or a tax accountant

Related guides

Business Registration & VAT (Self-employed)Claiming Tax Refunds
Check the official site (Hometax) ↗

This is general information and has no legal force. Taxes change every year and depend on your situation — always verify with official sources (NTS ☎126, Hometax, a tax accountant).
Last updated: 2026-06-09