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Every client, every filing, one screen.

See which of your clients have filed, which are stuck on a bad GSTIN, and which have bills waiting for review. Clients enter the data; your team handles the exceptions.

See what we build → Use the free tools

Your firm, Monday morning

Quillix firm dashboard: four things that need the partner this month, ordered by what stops a filing first, above the list of all clients with their GSTR-1 and GSTR-3B status

What we build

CA firms lose hours every month to work software could do: re-typing invoices, matching ledgers, chasing deadlines across dozens of clients. Our goal is to take that work off your team, so their time goes to judgment, advice and the clients themselves.

We started with GST, where the monthly grind is heaviest, and we're building out from there into financial statements, income tax, TDS and audit. Here's what's live today, and what's in the pipeline.

Live Audit-side app · subscription

GST Module

One screen per client, covering the whole GST month. The invoice your client raises is the GSTR-1 row and the Tally voucher, so nothing gets re-typed and the job left for your team is review.

  • Invoicing with GSTIN, HSN, slab and ledger mapping pre-filled
  • Sales and purchase OCR that reads a photographed paper bill
  • GSTR-1 prepared and checked before the portal sees it
  • Tally integration that sends masters and vouchers straight into TallyPrime with Quillix for Windows
Explore the GST Module → See pricing
In the pipeline Same clients, same data

The rest of the cycle

  • Portal integrationspush to the GST, e-invoice and e-way bill portals from Quillix
  • Financial Statementstrial balance, P&L and balance sheet from the books already in Quillix
  • Income Taxcomputations and returns built from the books
  • TDSdeductions tracked, returns and certificates prepared
  • Audit Documentsworkings and schedules assembled as you go

How we decide what to build

Three positions shape every product call we make. They are also the quickest way to tell whether we are the right fit for your firm.

The data already exists

Your clients already do half the work: they raise the invoices, keep the bills, run the bank account. We build on that instead of redoing it. Anything entered once flows everywhere it is needed, so no figure gets typed twice and no record lives in two places.

The output is the test

Software for CA firms gets judged on one thing: whether what it produces holds up. A return the portal accepts, a ledger that ties out, workings that survive an audit. Not the dashboard, not the charts. We start from the finished output and work backwards.

Tally stays where it is

Every Indian audit firm has a decade of muscle memory in Tally. Replacing it is not the job. We export to it cleanly, every time, so your team keeps the workflow it already knows.

How we work, in full: no fake urgency, no dark patterns, no roadmap dates we cannot hit →

Built inside a working practice.

Quillix is a partnership between a founder studying for the CA Final and a practising CA firm in Chennai. The firm pressure-tests every piece of compliance logic (voucher entries, GSTR-1 JSON shapes, RCM scenarios, B2CL thresholds) on real client books before it reaches another firm. If a feature cannot survive a filing day there, it does not ship.

Read who we are →
Chennai, Tamil Nadu Where the product gets tested
Independent, bootstrapped No investors, no growth theatre
Your data stays yours Export any time. Cancel and we delete
Free GST tools

Free tools your whole
firm can use today.

The same GST engine that powers the GST Module — a calculator, an invoice generator, an HSN finder and more. Free, accurate, right in your browser — with a free Quillix login.

Explore all 7 tools →
Finder
HSN / SAC Code Finder

Search by product or service name — or by code — to find the HSN/SAC code and its GST rate.

Open finder → Generator
GST Invoice Generator

Fill in seller, buyer and line items — get a GST-compliant invoice, ready to print or save as PDF.

Open generator → Calculator
GST Calculator

Add or remove GST at any rate, with the exact CGST + SGST or IGST split shown clearly.

Open calculator →
From the Quillix blog

Real GST problems.
Field notes from the filing room.

Workflow problems that trip firms up on filing day. No whitepaper theory.

Read all articles →
GSTR-1 · Filing
The 7 GSTR-1 mistakes behind most rejections

Wrong place of supply, B2CS rows that should be B2CL, HSN summary mismatches: what we see most often, why the offline utility flags them, and how to catch them before submission.

The seven, in order
  1. Wrong place of supply on inter-state invoices
  2. B2CS rows that should be B2CL
  3. HSN summary that doesn't tie to invoice totals
  4. Missing RCM flag on reverse-charge invoices
  5. Exempt items taxed at 5% (or worse, 18%)
  6. Invoice numbers over 16 chars or with special characters
  7. Cancelled invoices left in the B2B section
Read the full article →
8 MIN READ
ITC · 2A vs 2B
2A vs 2B vs your books: which one to trust

2A updates dynamically, 2B freezes monthly, and your books are whatever your client typed last night. Here's the priority order we follow and why it matters for ITC claims.

6 MIN READ
E-Invoicing
When does e-invoicing apply to your client? (2026 update)

The turnover threshold has dropped four times since 2020. Updated slabs, who's exempt, the IRP/IRN flow, and what happens if you miss the cutoff date.

5 MIN READ
Two ways in

Start with a tool you need today.
Or open a client store and file from it.

The tools need nothing but a login. The GST Module starts free: one client store, 100 invoices a month, no card on file.

Open the free tools → Explore the GST Module