A plain-English GST guide for small businesses

GST Guides By Bahify Team ·

If you’re running a small shop, wholesale outfit or service business in India, GST is one of those things you can either spend a week trying to understand — or pick up gradually and stay slightly confused forever. This guide is the short version: enough to know what you need, what you don’t, and what’s about to change.

Do I even need to register for GST?

You need GST registration if your annual turnover is above ₹40 lakh for goods (₹20 lakh for services), with lower thresholds for special-category states. Inter-state sellers and e-commerce sellers must register regardless of turnover.

If you’re below the threshold, registration is optional — but voluntary registration often makes sense once you sell to other businesses, since it lets them claim input tax credit from your invoices.

The GST slabs you actually deal with

  • 0% — essentials, unbranded food grains, milk, books.
  • 5% — packaged food, footwear, transport services.
  • 12% — processed food, mobile phones, some textile items.
  • 18% — the standard rate; most goods and services.
  • 28% — luxury and sin goods.

For each item you sell, Bahify lets you pick the HSN code once; it then auto-applies the correct slab everywhere.

The forms you’ll actually file

GSTR-1 is your monthly (or quarterly, depending on turnover) outward-supplies return. GSTR-3B is the summary return where you pay the tax. GSTR-9 is the annual return.

If your billing software is honest about the data it captures, all three are mostly auto-generated. If it isn’t, you spend a Saturday every quarter cleaning up spreadsheets.

E-invoicing — when does it kick in?

E-invoicing is currently mandatory for businesses with turnover above ₹5 crore. If you’re smaller than that, you don’t need it — but the threshold has dropped every couple of years, so it’s worth being on a system that supports it whenever you do cross over.

Three pitfalls we see all the time

  1. Wrong place of supply. If the buyer is in a different state, you charge IGST, not CGST+SGST. Get this wrong on invoices and reconciliation becomes a nightmare.
  2. Missing HSN codes. Required on every invoice above a turnover threshold. Late additions invite mismatches.
  3. Issuing credit notes informally. Returns and discounts must go through proper credit notes — not just adjusted in the next bill.

This article is a quick orientation, not legal advice. For your specific situation, talk to your CA or a GST practitioner.