Rule 37, Rule 42/43, GSTR-9, Supplier Risk — four compliance obligations that every GST-registered entity carries, that every CA handles manually, and that no software in India has automated. Until now.
GSTN processes every invoice you file and every return your suppliers file. The system knows your Rule 37 violations, your Rule 42 under-reversals, your GSTR-9 discrepancies. It issues notices when the statute allows. By then, the interest has compounded, the penalties are fixed, and the CA is explaining what should have been caught eleven months ago.
Every credit purchase starts a 180-day timer. The invoice sits in your purchase register. Your CA does reconciliation. Nobody checks whether each invoice was paid within 180 days. When the timer expires on a ₹4L invoice, the ITC reversal is ₹72,000 and the DRC-03 interest may already be ₹15,000. The GST officer will find it. Your software did not tell you.
The D1 formula requires C2 — not C1. C2 is total ITC minus blocked credits, minus exclusively taxable inputs, minus exclusively exempt inputs. Most CA firms skip the T-segregation step entirely and compute D1 on total ITC claimed. This has been wrong since 2017. The difference between correct and incorrect reversal on a ₹1Cr purchase can be ₹3–8 lakhs annually.
Annual returns require aggregating 12 months of 3B data and reconciling with portal records. Discrepancies between filed 3B returns and GSTR-9 entries are the single largest source of GST scrutiny notices. Most CA firms prepare GSTR-9 by manually keying figures from the portal. No systematic cross-check. No discrepancy detection before filing.
Under Section 16(2)(aa), ITC requires the supplier to have filed GSTR-1. A supplier who stops filing — for whatever reason — takes your ITC permanently. The standard process is to discover this during reconciliation, after the quarter is done, after the 3B is filed. A risk score computed before filing is the difference between chasing the supplier and losing the credit.
Each module is built directly from the statutory text. Not from a software interpretation of it. Every input, every formula, every output traces back to a specific provision.
Every invoice you buy on credit starts a 180-day clock. If your vendor is not paid within that window, GST law requires you to reverse the ITC — plus pay interest at 18% per annum from the original claim date via DRC-03. Most CA firms track this in Excel. Most miss invoices. The GST department does not.
Upload your Purchase Register. GSTAgent reads every invoice, computes the 180-day deadline, tracks payment status, and flags exactly what is overdue, what is due within 30 days, and what is safe. For overdue invoices it computes the exact DRC-03 interest liability down to the rupee.
The Rule 42 D1 formula is widely understood as D1 = Total ITC × (E/F). That is wrong. The provision requires computing C2 first. Here is the difference — and why it matters.
Total ITC from GSTR-3B, total exempt turnover, total turnover. Simple. Fast. Wrong.
We checked every major GST compliance platform in India. This is what the market looks like.
| Feature | GSTAgent | ClearTax | Tally | Excel |
|---|---|---|---|---|
| Rule 37 — per-invoice 180-day tracking | ✓ | — | — | — |
| DRC-03 interest computation at 18% p.a. | ✓ | — | — | — |
| Rule 42 with T1/T2/T3 segregation | ✓ | — | — | — |
| Section 17(5) auto-detection from HSN codes | ✓ | — | — | — |
| Capital goods 60-month Rule 43 schedule | ✓ | — | — | — |
| GSTR-9 working with discrepancy detection | ✓ | ✓ | — | — |
| GSTR-2B cross-check vs claimed ITC | ✓ | ✓ | — | — |
| Supplier risk scoring from reconciliation data | ✓ | — | — | — |
| WhatsApp follow-up templates per supplier | ✓ | — | — | — |
| All four modules in one platform | ✓ | — | — | — |
Drop your Purchase Register, GSTR-3B PDFs (up to 12 months), GSTR-2B, and GSTR-1 into the respective module. The engine auto-detects which month each file belongs to from the file's internal data — you don't label anything.
Every provision runs automatically. 180-day deadlines computed per invoice. T1/T2/T3 tagged from HSN codes. Section 17(5) blocked credits detected. GSTR-2B cross-checked. C2 computed. D1 formula executed per law.
Dashboard shows your audit health score, action items ranked by priority, and per-module status. Section 73/74 risk flags appear before any export. You see exactly what to fix before it reaches the portal.
Full audit report as multi-sheet Excel. Pre-filled GSTR-3B Table 4(B)(2) entries. WhatsApp templates for HIGH-risk suppliers. DRC-03 interest amounts. Everything your CA needs to file correctly the first time.
Files you upload for audit analysis are processed in your browser session. No invoice data, no purchase register, no supplier GSTINs are stored on our servers. The analysis happens locally and exports to your device.
GSTAgent reads the structure of your ERP exports, Tally registers, and portal PDFs. It does not upload them, parse them on a server, or associate them with your account. The engine runs on your machine.
Every export is structured as a working paper — provision reference, computed figures, formula breakdowns, and flagged items. The Excel exports are designed to accompany an audit file, not replace the CA's judgment.
A CA firm billing ₹10,000 per client for GST audit spends 2–3 days per client. The engine does it in 20 minutes. The ROI conversation writes itself.
Every rule, every provision, every formula — running in one engine. Open the Audit Engine and run your first analysis in under five minutes.