API access lets ERP and billing software generate, update and cancel bills programmatically. Access is arranged through a GST Suvidha Provider (GSP) or Application Service Provider (ASP), with an API user created on the portal.
Authentication
You authenticate to receive a short-lived token, then send it with each request. Token expiry and auth errors are the most common issues.
IP whitelisting
Production calls usually require your server IP to be whitelisted with the GSP. Unwhitelisted IPs are rejected even with valid credentials.
Best practices
Refresh tokens before expiry, validate GSTINs/HSN/dates before sending, and batch sensibly to avoid timeouts and duplicate-invoice errors.
Frequently asked questions
Do I need a GSP?
Most businesses access the API through a GSP/ASP partner.
Why is my IP rejected?
Production API access typically requires IP whitelisting with your GSP.