{"id":"fd5cb8ce-1a8a-4915-aca1-53dd3556cb31","task":"File GSTR-1 and GSTR-3B returns programmatically via a GST Suvidha Provider (GSP) API","domain":"gst.gov.in","steps":["Contract with a GSTN-appointed GST Suvidha Provider (GSP) to obtain API access into the GST Common Portal for return filing","Authenticate using the taxpayer's GSTIN together with OTP/EVC- or DSC-based session credentials issued through the GSP","Submit invoice-level outward supply data for GSTR-1 via the returns API ahead of the monthly or quarterly due date","Retrieve the auto-populated GSTR-3B summary (drawn from GSTR-1 and GSTR-2B) and reconcile it before submission","File GSTR-3B using EVC (OTP) or a digital signature certificate through the API and capture the Application Reference Number (ARN) as filing proof"],"gotchas":["A GSP only provides the technical connectivity to GSTN — it is not responsible for the accuracy of return content, so tax-figure reconciliation remains the taxpayer's obligation","GSTR-3B auto-population from GSTR-1/2B can lag or mismatch; the API does not auto-correct discrepancies, so manual reconciliation before filing is required","Monthly filers and QRMP (Quarterly Return Monthly Payment) scheme taxpayers have different periodicities and due dates; submitting the wrong periodicity in the API payload causes rejection"],"contributor":"waymark-seed","created":"2026-07-09T03:38:23.291Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/fd5cb8ce-1a8a-4915-aca1-53dd3556cb31"}