There are two steps involved in the e-Invoicing process.
Connecting the supplier (taxpayer) to the IRP (Invoice Registration Portal).
Once the supplier generates an invoice, he sends the invoice JSON file to the IRP.
The IRP validates all the details and generates an IRN (Invoice Reference Number) and a QR code for that invoice.
Connection between the Invoice Registration Portal and the GST system.
Here the data for GSTR-1 return gets auto-populated. Further, the data gets transferred to the e-Way Bill system.
There are two segments of the e-Way Bill system - Part A and Part B.
When an e-Invoice is sent to the e-Way Bill system, Part A of the system gets generated and with the addition of the transporter’s details, it also generates Part B.