GST setup guide — step by step
This guide walks a crackers (fireworks) business through configuring GST in BillBook so every bill and report comes out filing-ready. The short version of these steps also lives in the app under Settings › GST.
This guide configures the software. For scheme choices and thresholds, confirm with your accountant — it is not tax advice.
Before you start: which situation are you in?
| Your situation | Pick in Settings › GST | What your bills become |
|---|---|---|
| GST-registered, you collect tax from customers | Registered — regular scheme | TAX INVOICE with CGST/SGST or IGST |
| Registered under composition (turnover ≤ ₹1.5 Cr, you pay 1% yourself) | Registered — composition scheme | BILL OF SUPPLY, no tax, statutory declaration printed |
| No GSTIN (under the ~₹40 lakh goods threshold) | Not GST-registered | Plain INVOICE, no tax anywhere |
Facts that matter for crackers:
- Fireworks and pyrotechnic articles are HSN 3604, taxed at 18% (9% CGST + 9% SGST within your state, 18% IGST to other states). BillBook's product defaults already match.
- Composition dealers cannot make inter-state sales and cannot collect GST on bills.
- Turnover ≤ ₹5 Cr → 4-digit HSN ("3604") is sufficient on invoices.
- E-way bill: required from ₹50,000 (inter-state); intra-state thresholds vary by state (₹1,00,000 in Tamil Nadu). Both are configurable under Settings › Invoicing.
Step 1 — Pick your scheme
Settings › GST → GST Registration. Choose regular, composition, or not registered. Everything else — bill entry, printed titles, the GST reports screen — follows this choice.
Step 2 — Enter and verify your GSTIN
Type your 15-character GSTIN. BillBook validates the official format and check digit and shows the state it's registered in — that state is compared with each customer's GSTIN to auto-mark bills as inter-state (IGST) or within-state (CGST/SGST). The GSTIN prints in the header of every invoice.
Step 3 — Check your products
Every product carries an HSN code (default 3604) and a GST % (default 18). Review the Products screen; anything you sell that isn't fireworks (e.g. matches, gift boxes with different treatment) should get its correct HSN and rate. Bills pick these up automatically in the next step.
Step 4 — Turn on "Apply GST on bills" (regular scheme)
This is the switch that makes GST real on your bills:
- Picking a product on a bill now fills its HSN and GST % automatically.
- A GST % column appears in the bill's item table (editable per line).
- The bill's totals show the tax, split CGST/SGST or IGST by the inter-state flag.
Until you turn it on, billing behaves exactly as before (no tax on fast-entry bills) — so nothing changes behind your back.
Step 5 — Decide how your rates are quoted
Crackers price lists are usually GST-inclusive ("net rate" after the discount already contains tax). If that's you, switch on "Rates include GST":
- The total stays exactly what you type — a ₹100 rate stays a ₹100 bill.
- Tax is shown backed out: ₹100 at 18% prints as ₹84.75 taxable + ₹15.25 GST.
Leave it off if you quote ex-tax rates and add GST on top. Purchases are always treated as tax-exclusive (supplier bills quote ex-tax rates).
Optional: switch on "Auto round-off" to round every bill total to the nearest rupee (allowed under Sec 170) — the round-off line is computed for you.
Step 6 — Add your customers' GSTINs
On each wholesale customer, fill their GSTIN. Two things happen:
- Their invoices are classified B2B in GSTR-1 (with GSTIN); customers without one are B2C.
- Their state code auto-sets the inter-state flag on new bills — IGST instead of CGST/SGST — while staying editable per bill.
Step 7 — Bill normally
Nothing new to learn at the counter: pick products, type quantities, save. The invoice prints as a TAX INVOICE with your GSTIN, PESO licence, HSN-wise tax summary, amount in words, and CGST/SGST or IGST totals. Credit notes reverse the same tax they charged. The e-way bill warning still appears at your configured thresholds.
Composition scheme: bills print as BILL OF SUPPLY with the declaration *"Composition taxable person, not eligible to collect tax on supplies"* and no tax lines. The form warns you if a bill is marked inter-state.
Step 8 — File from the GST screen
GST in the sidebar (regular scheme) gives you, per financial year:
| Report | What it's for |
|---|---|
| GSTR-1 (invoices) | Invoice-wise outward supplies — B2B/B2C split, GSTIN, supply type, credit notes as negative rows |
| HSN summary | HSN-wise quantity, taxable value and tax (GSTR-1 Table 12) |
| Rate summary | Taxable/tax totals per GST rate — a quick sanity check |
| GSTR-3B | Outward tax payable, credit-note reductions, and inward purchases (ITC) |
Export any table as CSV and hand it to your accountant.
Filing calendar (regular): GSTR-1 by the 11th of the following month (or quarterly under QRMP if turnover ≤ ₹5 Cr), GSTR-3B by the 20th. Composition: CMP-08 quarterly (18th after quarter end), GSTR-4 annually — the Reports screen gives you the turnover figures.
Troubleshooting
- Bills show no tax after setup → confirm scheme is *regular* AND "Apply GST on bills" is on; then check the product's GST % isn't 0. Existing bills keep the tax they were saved with — edit and re-pick products to re-fill rates.
- Totals jumped 18% after enabling GST → your rates are GST-inclusive; switch on "Rates include GST" (Step 5).
- Wrong CGST/SGST vs IGST → check both GSTINs' first two digits (state codes) and the bill's inter-state checkbox.
- GSTIN marked invalid → it failed the official checksum; re-copy it from the GST registration certificate.
- A quotation converted to an invoice has no tax → estimates are quoted without GST by design; open the invoice's edit screen and re-pick the products to fill rates.