Korea Payroll & Tax API › overtime-pay

South Korea overtime, night and holiday work premiums under the Labor Standards Act (1

South Korea overtime, night and holiday work premiums under the Labor Standards Act (1.5x overtime, +0.5x night, 1.5x/2x holiday); workplaces with fewer than 5 employees get no premium.

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

Input

Field	Type	Required	Description
`wage`	number	yes	Hourly wage, or monthly ordinary wage when unit is monthly (KRW)
`unit`	hourly \| monthly		hourly, or monthly (divided by 209 hours); default hourly
`overtimeHours`	number		Overtime hours
`nightHours`	number		Night hours (22:00-06:00); also enter them as overtime if they overlap
`holidayHours`	number		Holiday work hours up to 8 per day
`holidayHoursOver8`	number		Holiday work hours beyond 8 per day
`fiveOrMoreEmployees`	boolean		Workplace has 5 or more employees; default true

Example request

curl -X POST https://api.kkuldogu.com/v1/overtime-pay -H "content-type: application/json" \
  -d '{"wage":12000,"overtimeHours":10,"nightHours":4,"holidayHours":8}'

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": "overtime-pay",
  "input": {
    "wage": 12000,
    "overtimeHours": 10,
    "nightHours": 4,
    "holidayHours": 8
  },
  "result": {
    "total": 348000,
    "hourlyBase": 12000,
    "overtime": 180000,
    "nightPremium": 24000,
    "holiday": 144000,
    "holidayOver8": 0,
    "multipliers": {
      "overtime": 1.5,
      "nightPremium": 0.5,
      "holiday": 1.5,
      "holidayOver8": 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