Creating e-Invoice API Login Credentials


This article describes the procedure to create e-Invoice API login credentials in the e-Invoice Sandbox Portal and e-Invoice API Portal setup by National Information Centre (NIC). Here’s a PDF of the API registration article if you would like to download it.

Part 1: Registering in Sandbox portal and Entering details in GSTZen

To begin your e-Invoice testing, you will first need to acquire API credentials from the government Sandbox portal. Unique Username and Password has to be created for each GST number. After this, you would enter these credentials into GSTZen

Section 1: e-Invoice API Registration in NIC Trial Portal

NIC Sandbox portal

  • Click on Login and then, click on Register here

NIC registration

  • You will be able to see a similar screen after clicking on Register here. Select Taxpayer on Registration Form.

NIC Taxpayer Registration

  • Enter the GSTIN, Phone number, and Email address registered with GSTIN, and Captcha. Click on the Validate button to validate the information. The portal will validate the data. After that, click on the Send OTP button

Enter Taxpayer Information

  • Enter the OTP received on the registered mobile and click on Submit

Enter OTP

  • You will be able to see your GSTIN on this page. Select Registration through as GSP.
  • Enter the Client ID as AAFCC29ERP82ZSO. Enter your API testing Username and Password  & Click on Create.

Create API Username

  • You will now be able to see the acknowledgment from the e-Invoice portal.

eInvoice acknowledgement

Section 2: Logging into the NIC Trial Portal through GSTZen


Note: GSTZen recommends using 2 different accounts for Sandbox testing and Production.

  • Register your GSTIN in your GSTZen account. For information on how to add your GSTIN into GSTZen, please see the article – Add GSTIN to your GSTZen account
  • Click on the GSTIN to open your GSTZen Home page. Click on e-Invoicing

GSTZen Homepage

  • Choose Tally/SAP Integration

TallySAP e-Invoice Integration

  • Enter your API Username and Password from the Sandbox portal

GSTZen e-Invoice trial

Note: Client ID and Client Secret to be entered in GSTZen is  ZENTRIAL


Part 2: Registering in API production portal and Entering details in GSTZen


Since the testing credentials cannot be used to create Live e-Invoices, you would need to sign up for production API credentials. If you wish to continue into production with the same GSTZen credentials, the test Sales invoices will need to be deleted from your account.

Section 1: Delete all your invoices in the sales register


  • Select the GSTIN on your GSTZen Homepage dashboard.

Choose GSTIN

  • Click on the Sales Register on the right side of your screen.

GSTZen sales register

  • Select the checkbox next to Type as shown in the below picture and then click on Delete selected invoices in page.

GSTZen einvoice list

  • Select the Approve checkbox and click on Delete Invoices.

Delete e-invoice

Section 2: API e-Invoice Registration in Production e-Invoice Portal


API e-invoice portal

  • Click on Login and enter your Username and Password

Note: If you have registered on the Eway bill production portal, you may use the same credentials to log in to the API e-Invoicing portal

e-Invoice API login

  • Click on API Registration.

e-Invoice Dashboard

  • Click on User Credentials and click on Create API User. This will trigger an OTP to your registered mobile Number.

Create e-Invoice API user

  • Please enter the OTP and click on Verify OTP.

e-Invoice OTP

  • Click on Through GSP.

Through ERP


Choose e-Invoice ERP

  • Create API-specific Username and Password & Click on Submit.
  • Your API credentials are created, you receive a message that the user creation was successful.

e-Invoice API creation

Section 3: Logging into the API Portal through GSTZen

  • Click on E-Invoicing on your GSTIN detail page.

GSTZen Homepage

  • Choose Tally/SAP Integration

Tally SAP e-Invoice Integration

  • Click on Change E-Invoice Portal Login details.

Update e-Invoice credentials

  • Provide Client ID and Client Secret as ZENLIVE. Please note that the username will start with API_