In an e-invoicing system, APIs (Application Programming Interface) facilitate the communication and exchange of data between taxpayers and the GST portal.
Under this system, a unique IRN (Invoice Reference Number) gets issued by the IRP (Invoice Registration Portal) against every invoice generated. All the invoice details get transferred to both the GST portal as well as the NIC (National Informatics Centre) portal in real-time via APIs. This eventually eliminates manual processing and helps businesses to file GST returns and to claim GST refunds with ease.