FillGST Helper

About

FillGST Helper — companion extension for the FillGST web app (fillgst.com)

If you're an Indian CA, a corporate tax team, or an SMB owner filing your own GST returns, you've probably lived this: open the GST portal, paste the captcha, enter the OTP, fetch GSTR-2B, switch to Tally or Excel, manually reconcile invoices, jump back to the portal because the session expired, enter another OTP, then start over. Saturday gone.

FillGST Helper kills that loop.

It's a thin Chrome extension that does exactly two things: (1) lets the FillGST web app at fillgst.com fetch your own GSTR-2B, filing status, and system-generated GSTR-3B directly from gstn.gov.in using your already-logged-in browser session — no OTP after the first one of the day — and (2) optionally bridges your local TallyPrime so books data flows into FillGST without exporting XML. Everything is orchestrated inside your own browser; no credentials ever leave your computer.

WHAT THE EXTENSION ACTUALLY DOES
- Zero-OTP GSTN fetch — pulls 2B, filing status, system 3B and matched invoices in 2–3 seconds, using the GSTN session you already created by logging in normally
- Local Tally bridge (optional) — talks to TallyPrime running on the same machine over its local HTTP port; pulls voucher data into the FillGST web app without exporting XML
- Status push-back — tells the FillGST tab when a fetch completes so reconciliation can refresh without manual page reloads
- Per-host scope — only runs on gstn.gov.in and fillgst.com; ignores every other tab and site you have open

WHO IT'S FOR
- CA firms managing dozens or hundreds of GSTINs — bulk-fetch 2B and filing status for every client in one batch
- Corporate tax teams with multi-GSTIN entities and SOX-style controls
- Solo CAs filing for their own client list
- Individual filers — sole proprietors, freelancers, small businesses doing their own GSTR-1 / 3B

WHAT MAKES THE BUNDLE WORK
The extension is the connector. The actual filing workflow lives in the FillGST web app (fillgst.com), which:
- Covers all 24 return forms — GSTR-1, 3B, 9, 9C, 4, 6, 7, 8, IMS, ITC-04, e-invoice, e-waybill, the rest
- Reconciles books vs 2B with Sec 16(2)(c) flagging and Rule 88A waterfall offset calculation
- Cites the section, rule or notification behind every routing decision (Sec 17(5), Notif 14/2022, Circular 170, Jul-2025 hard-lock, etc.) so what you file is what defends in audit
- Signs and files with your real DSC USB token, PFX, or EVC — private key stays on the same machine that holds it now

PRIVACY (this is the whole point)
- Your GSTN password, OTP, and DSC private key never leave your computer
- The extension does not hold any portal credentials. It only borrows the session you've already created by logging in normally
- No analytics, no telemetry, no third-party scripts loaded
- The only domains the extension talks to are gstn.gov.in (the GST portal, on your behalf) and fillgst.com (your own subscribed workspace)
- Mumbai-headquartered, DPDP-compliant

FREE TIER
- 1 GSTIN, 5 returns a month — forever
- Pay ₹499/mo Starter only when you need more