GST APIs
Verify and retrieve GST (Goods and Services Tax) information for businesses registered under the Indian GST system. These APIs provide real-time access to GSTIN status, compliance ratings, filing details, filing preferences, and e-invoice applicability — essential for vendor onboarding, invoice validation, and tax compliance.
Use cases
| Industry | Use case |
|---|---|
| Businesses & corporates | Verify supplier GSTIN before onboarding vendors |
| Billing & invoicing | Confirm GSTIN status before issuing or accepting GST invoices |
| Tax & accounting firms | Monitor filing compliance of clients and their vendors |
| E-commerce platforms | Validate seller GSTINs for regulatory compliance |
| Banks & financial institutions | Verify GSTIN for loan applications and credit assessments |
| ERP integrations | Automate GSTIN checks in procurement and invoicing workflows |
Available endpoints
| Endpoint | Method | Path | Description |
|---|---|---|---|
| GSTIN Status | GET | /vas-api/gstn-status-v1 | Check registration status, business details, and tax type |
| GSTIN Rating | POST | /vas-api/v1/gstin-rating | Get monthly compliance rating (1-5 scale) |
| GST Filing Details | GET | /vas-api/v1/gst-filing-details | Retrieve filing history with ARN, dates, and modes |
| Filing Preference | GET | /vas-api/v1/filing-preference | Get filing frequency (monthly vs quarterly) |
| e-Invoice Applicability | GET | /vas-api/e-invoice-applicability-v1 | Check if GSTIN requires e-invoicing |
| PAN to GSTIN | GET | /vas-api/v1/pan-to-gstin | Find all GSTINs linked to a PAN |
Authentication
All GST endpoints require an OAuth2 Bearer token. You need to:
- Sign up for a developer account
- Get an access token using your client credentials
- Include the token in every request:
Authorization: Bearer YOUR_ACCESS_TOKEN
Quick example
Check the status of a GSTIN:
bash
curl -X GET "https://api.api4business.com/vas-api/gstn-status-v1?gstin=29ABCDE1234F1Z5" \
-H "Authorization: Bearer YOUR_ACCESS_TOKEN"Error handling
All GST endpoints return errors in a consistent format. See GST Error Codes for the complete list, or the Error Handling Guide for retry patterns.
What's next
- GSTIN Status — Start with the most common GST check
- Quick Start — Make your first API call in under 10 minutes
- Error Codes — All GST-specific error codes
- Changelog — Version history for GST APIs