Korea Payroll & Tax API › stock-transaction-tax

South Korea securities transaction tax on selling listed shares (2026 rates)

South Korea securities transaction tax on selling listed shares (2026 rates): KOSPI 0.05% plus 0.15% rural special tax, KOSDAQ 0.20%, charged on the sale amount whether or not there is a gain.

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

Input

Example request

curl -X POST https://api.kkuldogu.com/v1/stock-transaction-tax -H "content-type: application/json" \
  -d '{"sellAmount":10000000,"market":"kospi"}'

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, 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": "stock-transaction-tax",
  "input": {
    "sellAmount": 10000000,
    "market": "kospi"
  },
  "result": {
    "total": 20000,
    "securitiesTransactionTax": 5000,
    "ruralSpecialTax": 15000,
    "totalRatePct": 0.2,
    "netProceeds": 9980000
  }
}

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