{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Invoice",
  "type": "object",
  "description": "An invoice document submitted by a supplier for goods or services delivered against a purchase order",
  "properties": {
    "invoiceId": {
      "type": "string",
      "description": "Internal unique invoice identifier"
    },
    "invoiceNumber": {
      "type": "string",
      "description": "Supplier-assigned invoice number"
    },
    "invoiceDate": {
      "type": "string",
      "description": "Date the invoice was issued"
    },
    "invoiceType": {
      "type": "string",
      "description": "Type of invoice document"
    },
    "purchaseOrderReference": {
      "type": "string",
      "description": "Primary purchase order number this invoice relates to"
    },
    "currency": {
      "type": "string",
      "description": "ISO 4217 currency code"
    },
    "dueDate": {
      "type": "string",
      "description": "Payment due date"
    },
    "lineItems": {
      "type": "array",
      "description": "Invoice line items"
    },
    "taxDetails": {
      "type": "array",
      "description": "Header-level tax summary"
    },
    "comments": {
      "type": "string",
      "description": "Invoice comments or notes"
    },
    "approvalDate": {
      "type": "string",
      "description": "Date the invoice was approved"
    },
    "paymentDate": {
      "type": "string",
      "description": "Date payment was made"
    },
    "paymentReference": {
      "type": "string",
      "description": "Payment transaction reference number"
    },
    "createdDate": {
      "type": "string",
      "description": "Timestamp when the invoice was created in the system"
    },
    "lastModifiedDate": {
      "type": "string",
      "description": "Timestamp of the last modification"
    }
  }
}