Korea Payroll & Tax API › vat

South Korea 10% VAT

South Korea 10% VAT: split a VAT-inclusive total into supply amount and VAT, or add VAT to a supply amount, with Korean rounding.

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

Input

Field	Type	Required	Description
`amount`	number	yes	Supply amount, or VAT-inclusive total when mode is total (KRW)
`mode`	supply \| total		amount is the supply amount (default) or the VAT-inclusive total

Example request

curl -X POST https://api.kkuldogu.com/v1/vat -H "content-type: application/json" \
  -d '{"amount":1100000,"mode":"total"}'

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": "vat",
  "input": {
    "amount": 1100000,
    "mode": "total"
  },
  "result": {
    "supplyAmount": 1000000,
    "vat": 100000,
    "total": 1100000
  }
}

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