Debit and Credit Notes

For debit and credit notes, the structure is largely the same and still uses the Invoice class. You need 3 extra things:

• Ensure the invoice type subcode is set according to this page.
• Add an instruction_note
• Add a billing reference (reference to the original invoice the note is being issued for)

credit_note = Invoice.new(
  # ... other properties
  instruction_note: "Refunded because customer ordered by mistake",
  
  # Make sure to follow this format as it is what ZATCA expects
  billing_reference: "Invoice Number: 354; Invoice Issue Date: 2021-02-10",

  # Either :debit or :credit
  subtype: ZATCA::UBL::Invoice::INVOICE_TYPE_CODES[:credit]
)