Korea Payroll & Tax API › inheritance-shares

South Korea statutory inheritance shares and forced-heirship reserve (yuryubun) under the Civil Code

South Korea statutory inheritance shares and forced-heirship reserve (yuryubun) under the Civil Code: heirs by rank (children, then parents, then siblings), the spouse 50% add-on, and reserved portions (1/2 of the share for children and spouse, 1/3 for parents, none for siblings). Representation (daeseup) and heirs beyond siblings are not modeled.

Price: $0.10 USDC per call over REST (x402 on Base, no API key). MCP: paid-only — the MCP tool returns payment instructions. Basis year: 2026.

Input

Field	Type	Description
`spouse`	boolean	Surviving legally married spouse; default false
`children`	integer	Number of children (lineal descendants of the nearest degree)
`parents`	integer	Number of surviving parents (lineal ascendants of the nearest degree); inherit only if there are no children
`siblings`	integer	Number of siblings; inherit only if there is no spouse, child or parent
`estate`	number	Estate value, to get amounts (KRW)

Example request

curl -X POST https://api.kkuldogu.com/v1/inheritance-shares -H "content-type: application/json" \
  -d '{"spouse":true,"children":2,"estate":700000000}'

Without payment this returns 402 with x402 payment requirements; an x402 client pays $0.10 USDC and retries.

Example response

{
  "basisYear": 2026,
  "currency": "KRW",
  "disclaimer": "For reference only, not legal, tax or financial advice. Computed from South Korean statutes and standard formulas as of 2026; reliefs, exemptions and special cases not shown in the result are not modeled, and rules may have changed. Confirm with the relevant office, court, lender or a professional before acting.",
  "source": "https://kkuldogu.com",
  "tool": "inheritance-shares",
  "input": {
    "spouse": true,
    "children": 2,
    "estate": 700000000
  },
  "result": {
    "rank": 1,
    "heirs": [
      {
        "heir": "spouse",
        "share": "3/7",
        "sharePct": 42.86,
        "amount": 300000000,
        "reservedShare": "3/14",
        "reservedAmount": 150000000
      },
      {
        "heir": "child",
        "share": "2/7",
        "sharePct": 28.57,
        "amount": 200000000,
        "reservedShare": "1/7",
        "reservedAmount": 100000000,
        "count": 2
      }
    ]
  }
}

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