Korea Payroll & Tax API › social-insurance

South Korea four major social insurances (national pension, health, long-term care, employment) for a monthly wage

South Korea four major social insurances (national pension, health, long-term care, employment) for a monthly wage: employee deductions and employer contributions at 2026 rates.

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

Input

Field	Type	Required	Description
`monthlyPay`	number	yes	Gross monthly pay (KRW)
`nonTaxable`	number		Monthly non-taxable allowances; default 200000 (KRW)
`employerSize`	under150 \| 150plus_priority \| 150to999 \| 1000plus		Employer headcount bracket for the employer employment-insurance rate; default under150

Example request

curl -X POST https://api.kkuldogu.com/v1/social-insurance -H "content-type: application/json" \
  -d '{"monthlyPay":3500000}'

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": "social-insurance",
  "input": {
    "monthlyPay": 3500000
  },
  "result": {
    "insurableMonthly": 3300000,
    "employeeTotal": 320660,
    "employerTotal": 328910,
    "payAfterInsurance": 3179340,
    "employee": {
      "nationalPension": 156750,
      "healthInsurance": 118630,
      "longTermCare": 15580,
      "employmentInsurance": 29700
    },
    "employer": {
      "nationalPension": 156750,
      "healthInsurance": 118630,
      "longTermCare": 15580,
      "employmentInsurance": 37950
    }
  }
}

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