Guide to Obtain APIs for e-Invoice Generation - Requirements And Best Practices


Date: 29 Dec 2022

GST E-Invoicing API: Who Can Access It, What Are The Requirements, And The Best Practices


Application Programming Interface (API) is software that enables the communication between applications. APIs provide data exchange and communication between taxpayers and GSPs (GST Suvidha providers) regarding the e-invoice system. Two software components will need to interact with one another following the API standard for the government to construct a platform to provide GST services to taxpayers. The e-invoice system uses RESTful web services to offer taxpayers with various operations like submitting returns, registering, examining ledgers, making online payments, etc.


Uses Of API 

The APIs will then transport the data to the e-way bill and GST portals once the taxpayer has submitted it in their ERP.


Turnover In the Previous Financial Year Applicable Date
More Than Rs. 500 Crore 1st October 2020 (Mandatory With Certain Exemption)
More Than Rs. 100 Crore and Less Than Rs. 500 Crore 1st January 2021 (Mandatory With Certain Exemptions)
More Than Rs. 50 Crore 1st April 2021
More Than Rs. 20 Crore 1st April 2022
More Than Rs. 10 Crore 1st October 2022



**Revenue made from 2017–18 to 2021–22. Financial institutions, NBFCs, the GTA, and passenger transportation services have all been granted exemptions from e-invoicing and QR code generation.


What Is The Purpose Of Using APIs Under GST? 

The ease of the taxpayer is essential for a successful GST implementation.  Third-party software that offers a range of user interfaces on desktops, laptops, and mobile devices, can connect to the GST filing system. The taxpayer's confidence is increased due to these third-party applications' connection to the GST filing system via GST APIs.


Taxpayers will produce electronic invoices using their ERP software and report them on the invoice registration portal under e-invoicing (IRP). The e-invoice process has been built by the IRP using an API mode. The GSPs and taxpayers can include these APIs in their current ERP systems and use them to produce E-Invoices immediately.


Types Of APIs

Below are different types of APIs.

  • Authentication

  • Generate Invoice Reference Number (IRN)

  • Cancel IRN

  • Get IN Details

  • Generate e-way bill by IRN

  • Get GSTIN Details 

  • Cancel E-way bill

  • Sync GSTIN Details From CP (Common Portal)

  • Get e-way bill details by IRN

  • Get IRN details by document details

  • Health API


How Does API Help In Generating E-Invoices?

API is crucial in the generation of the E-Invoice. The information from the taxpayers' invoices must be entered into their accounting software. The invoice registration portal receives the data after being supplied via the API (IRP). The invoice is delivered and returned to the taxpayer with the digitally signed e-invoice and QR code after being registered under the IRP, an IRN being produced. The invoice is prepared for printing by the taxpayer's system and includes the IRN and QR code.


What Are the Benefits Of Using APIs?

  • APIs provide seamless connectivity between the taxpayer's ERP/accounting system and the e-invoice solution.  

  • APIs will prevent duplicate or dual input of an invoice or IRN because the outward supply invoices are first entered into the taxpayer's ERP and then transferred to the electronic invoicing system.

  • APIs aid in the elimination of data entry errors in e-invoices. 

  • The taxpayer must only enter the information once into their ERP, after which the APIs will transport it to the e-way bill and GST portals.


Prerequisites For Using API For E-Invoice 

Below are some of the requirements for using API for E-Invoice

  • Taxpayers and GSPs must automate their invoice generation procedure.

  • GSPs and taxpayers must ensure that there are no viruses, spyware, intrusions, bots, or other harmful components in the traffic going from their end to the e-invoice system. If the NIC detects any malicious traffic, the service can be suspended.

  • The Indian government requires GSPs and taxpayers to abide by all IT security guidelines and legal obligations.  

  • GSPs and taxpayers must adhere to the authorities' infrastructure and application security standards.

  • The Information Technology Act of 2000, including Section 43A, and its revisions, must be complied with by GSPs and taxpayers. 

  • To access the production environment, taxpayers must identify four Indian static IP addresses. 

  • A pre-production testing system is required to use various activities or services.  


When You Use Third-Party Applications For E-Invoicing

There is a three-level interaction if one employs application service providers (ASP) to generate IRN. The client's accounting or billing system is accessed by the ASP, which then extracts the invoice data and formats it for transmission to the IRP. Using APIs, the interaction takes place. Due to the associated cost-effectiveness, this model is a somewhat appealing choice for most taxpayers. On the other hand, the taxpayers' own ERP system can simply communicate with the IRP to generate IRNs if it has API access to the IRP.

Busy accounting software will help you generate GST e-invoicing without any hassle.