E-invoicing’ or ‘electronic invoicing’ is a system where in the tax payer will upload his invoice details and register his supply transaction on the Government Invoice Registration Portal (IRP) and get the Invoice Reference Number (IRN) generated by the IRP system. That is, the tax payer will first prepare and generate his invoice using his ERP/accounting system or manually to GeSTup from where these invoice details will be uploaded to IRP in order to get the unique reference number, known as IRN.