GST is the single biggest compliance headache for Indian shops. SaathiX ERP turns the monthly ritual into a 15-minute review: your invoices, purchases and adjustments are already there, we just format them the way GSTN expects. This guide covers the full cycle — from IRN generation the moment you save a B2B invoice, to filing GSTR-3B and matching GSTR-2B against your books.
01Set up GST once
Open Settings → GST. Enter your 15-digit GSTIN, choose your filing frequency (Monthly or QRMP), tick 'Composition scheme' if applicable, and add the API credentials for the e-invoice and e-way bill portals. SaathiX ERP validates the credentials with a test call — a green badge means you're live.
02e-Invoice (IRN) generation
If your turnover crossed Rs. 5 crore in any year from 2017-18 onwards, every B2B tax invoice must carry an IRN and signed QR code from the NIC portal. Turn on Settings → GST → e-Invoice; from that point every B2B invoice you save is pushed to the IRP within 3 seconds. The IRN, acknowledgement number and QR code are printed on the invoice automatically. If the IRP is down, the invoice queues locally and retries every minute — you never lose an invoice.
03e-Way Bill
For consignments above Rs. 50,000, SaathiX ERP can generate an e-way bill in one click from the saved invoice. Enter vehicle number and transport mode; the EWB number, valid-till date and part-A/B slip are attached to the invoice. Bulk generation is available under Dashboard → GST → e-Way for dispatch teams handling 50+ challans a day.
04GSTR-1 (outward supplies)
Open Dashboard → GST → GSTR-1. The screen shows five tabs — B2B, B2C-Large, B2C-Small, Exports and Nil Rated — pre-filled from your saved invoices. Every row is editable; changes here don't touch the original invoice. Click Reconcile to compare the counts with what's already on the portal (useful mid-month for QRMP IFF), then Prepare JSON to download the offline utility file or File Directly if you've added your EVC / DSC.
05GSTR-3B (summary return)
3B pulls three numbers per rate slab: taxable value, tax collected and ITC claimed. SaathiX ERP derives the first two from GSTR-1 automatically. ITC comes from your Purchases module minus a 'blocked credit' filter (Rule 42/43, personal expenses, ineligible items). Review the auto-populated table, add any RCM liability under 3.1(d), and file — most shops finish 3B in under five minutes.
06GSTR-2B matching
Under GST → 2B Recon, upload your GSTR-2B JSON or connect the portal API. SaathiX ERP matches every line to a purchase in your books using invoice number, date, GSTIN and taxable value with a 2% tolerance on tax. Mismatches show up in three buckets: 'In books not in 2B', 'In 2B not in books' and 'Value mismatch'. One-click actions let you accept the 2B version, mark the missing purchase for follow-up, or park the difference until next month.
07QRMP and IFF
Quarterly filers can push B2B invoices to the portal in the first two months of every quarter using IFF (Invoice Furnishing Facility). SaathiX ERP shows an IFF button on GSTR-1 during those months; the third-month filing runs the full return. Cash ledger challan (PMT-06) for monthly tax payment is generated from Dashboard → GST → Payments.
08What we don't do (and why)
SaathiX ERP does not file GSTR-9 / 9C annual returns directly — the reconciliation logic differs per business and is best done with your CA. We do generate a fully-formatted GSTR-9 workpaper (PDF + Excel) with every ledger and adjustment cross-referenced, which most CAs accept without changes.