In case of e-Invoicing, the user can get access to the GST portal services via GSP (GST Suvidha Provider) and comply with the provisions of the GST laws through their APIs. GSP need not be only ERP companies but can be startups or financial technology companies having expertise in building web applications for filing GST returns.
A taxpayer creates a username and password for his GSTIN to generate IRNs. Now to connect to the APIs and get access to those details via GSPs the user must create a new API username and password and request for respective IRNs from his system.