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GSTR-3B API

GSTR-3B is a monthly or quarterly GST summary return for declaring tax liability and paying GST for a tax period. Use this API to fetch GSTR-3B details, auto-calculate liability, save return data, offset liability using cash and ITC, and file GSTR-3B with EVC OTP authorization.

Why use this API

GSTR-3B filing is mandatory for all regular GST-registered taxpayers. This API automates the complete workflow, from fetching portal data to filing with authorized signatory verification, following GST compliance requirements for Form GSTR-3B.

Fetch & validate

Retrieve saved GSTR-3B data and auto-calculated liability from the GST portal for any return period.

Save & process

Upload GSTR-3B JSON to the portal and poll return status until validation completes.

Offset liability

Allocate Input Tax Credit (ITC) and cash ledger balance to offset tax liability before filing.

File with EVC

Generate EVC OTP for authorized signatory and file GSTR-3B after liability offset.

Recipes

Follow step-by-step guides for common GSTR-3B workflows:

API categories

GSTR-3B data APIs

APIMethodPath
Get GSTR-3B DetailsGET/gst/compliance/tax-payer/gstrs/gstr-3b/{year}/{month}
Get GSTR-3B Liability Auto CalcGET/gst/compliance/tax-payer/gstrs/gstr-3b/{year}/{month}/auto-liability-calc

Return filing APIs

APIMethodPath
Save GSTR-3BPOST/gst/compliance/tax-payer/gstrs/gstr-3b/{year}/{month}
Offset LiabilityPOST/gst/compliance/tax-payer/gstrs/gstr-3b/{year}/{month}/offset-liability
File GSTR-3BPOST/gst/compliance/tax-payer/gstrs/gstr-3b/{year}/{month}/file

Ledger APIs

APIMethodPath
Get Balance LedgerGET/gst/compliance/tax-payer/ledgers/bal/{year}/{month}

Status polling APIs

APIMethodPath
GST Return StatusGET/gst/compliance/tax-payer/gstrs/{year}/{month}/status

Authentication APIs

APIMethodPath
Generate EVC OTP (requires PAN and gstr=gstr-3b query parameter)POST/gst/compliance/tax-payer/evc/otp

Common use cases

Use GSTR-3B API when you need to:
  • Automate GSTR-3B filing from ERP or accounting software across multiple return periods
  • Track GSTR-3B processing status with return polling in a filing dashboard
  • Catch validation errors after save and offset operations before filing
  • Handle nil returns for inactive GSTINs using the File Nil GSTR-3B recipe

FAQs

GSTR-3B is a monthly or quarterly self-declaration summary return for GST-registered taxpayers in India. All regular taxpayers must file GSTR-3B to declare tax liability, claim Input Tax Credit (ITC), and pay GST for each return period. The return consolidates sales, purchases, and tax liability into one submission. See the GST API overview for terminology and authentication prerequisites.
The GSTR-3B filing workflow has eight steps. First, fetch existing return data and auto-calculate liability for validation. Next, save the return JSON to the portal and poll status until save completes. Then offset liability using ITC and cash, and poll status until offset completes. Finally, generate EVC OTP for the authorized signatory and file the return with OTP verification.
The GST portal processes save and offset requests asynchronously. Polling the GST Return Status endpoint confirms when processing completes and catches validation errors before you proceed to the next step.
EVC (Electronic Verification Code) OTP is a one-time password sent to the authorized signatory’s registered mobile or email. EVC OTP authenticates the signatory before filing GSTR-3B. Generate the OTP using the Generate EVC OTP endpoint with the signatory’s PAN.
Regular GSTR-3B is filed when a taxpayer has transactions, tax liability, or ITC claims for the period. Nil GSTR-3B is filed when there are no outward or inward supplies, no liability, and no ITC for the period. Nil filing is still mandatory to maintain compliance. Use the File Nil GSTR-3B recipe for nil returns.
Liability offset allocates Input Tax Credit (ITC) and cash ledger balance to pay tax liability. The Offset Liability endpoint lets you specify how much ITC and cash to apply to each tax head (IGST, CGST, SGST, cess). Liability offset must complete before filing.