{
  "type": "object",
  "properties": {
    "identifier_number": {
      "type": "string",
      "description": "The receipt or work order number that uniquely identifies this document"
    },
    "subtotal": {
      "type": "string",
      "description": "The subtotal amount before tax"
    },
    "tax": {
      "type": "string",
      "description": "The tax amount"
    },
    "total_due": {
      "type": "string",
      "description": "The total amount due"
    }
  },
  "required": [
    "identifier_number",
    "subtotal",
    "tax",
    "total_due"
  ]
}