Solution Architecture

1. ERP/accounting system submits an invoice/credit or debit note to the DigiTax ingestion flow.

2. The payload schema check validates the submitted invoice.

   • If the schema check fails, an error is returned to the ERP and the flow stops.

3. If the schema check passes, the invoice proceeds into the DigiTax system.

4. DigiTax generates an IRN (invoice reference number) and prepares the QR code data, then saves the invoice, IRN and QR code to the database.

5. DigiTax submits the invoice to FIRS for validation.

6. FIRS returns a validation response to DigiTax.

7. If the validation response indicates an error, DigiTax returns the validation error response to the ERP.

8. If validation is successful, DigiTax submits a signing request to FIRS.

9. FIRS returns the signing response (signed invoice / confirmation) to DigiTax.

10. DigiTax returns the final response to the ERP — this includes the invoice data, IRN number and QR code data.

Notes:

• The initial API response (implied earlier) confirms invoice creation on DigiTax, but the QR code is available only after signing/IRN generation.
• Error handling occurs at schema validation and FIRS validation stages; success moves the invoice forward to signing and finalization.