Korea Payroll & Tax API › other-income-tax

South Korea other-income (gita sodeuk) withholding of 22% on income after deemed expenses, e

South Korea other-income (gita sodeuk) withholding of 22% on income after deemed expenses, e.g. lecture fees, manuscript fees and prizes, with the KRW 50,000 exemption threshold.

Price: $0.01 USDC per call over REST (x402 on Base, no API key). MCP: free as other_income_tax at https://api.kkuldogu.com/mcp. Basis year: 2026.

Input

Field	Type	Required	Description
`amount`	number	yes	Gross payment (KRW)
`expenseRate`	0.6 \| 0.8 \| 0		Deemed expense rate: 0.6 (lectures, manuscripts, advisory), 0.8 (public-interest prizes) or 0; default 0.6

Example request

curl -X POST https://api.kkuldogu.com/v1/other-income-tax -H "content-type: application/json" \
  -d '{"amount":500000}'

Without payment this returns 402 with x402 payment requirements; an x402 client pays $0.01 USDC and retries.

Example response

{
  "basisYear": 2026,
  "currency": "KRW",
  "disclaimer": "For reference only, not legal or tax advice. Uses official 2026 Korean rates and the same formulas as the kkuldogu.com calculators; actual payroll, NHIS/NPS notices and tax settlement can differ.",
  "source": "https://kkuldogu.com",
  "tool": "other-income-tax",
  "input": {
    "amount": 500000
  },
  "result": {
    "net": 456000,
    "taxableIncome": 200000,
    "incomeTax": 40000,
    "localIncomeTax": 4000,
    "effectiveRatePct": 8.8
  }
}

For reference only, not legal or tax advice. Uses official 2026 Korean rates and the same formulas as the kkuldogu.com calculators; actual payroll, NHIS/NPS notices and tax settlement can differ. · Calculators for people (Korean): kkuldogu.com · API home · llms.txt · OpenAPI