← All articles

How to Make a GST-Compliant Medical Bill for Your Pharmacy

Updated 4 July 2026 · 7 min read

A tax invoice that's missing a field isn't just untidy — it can be rejected for input-tax-credit and flagged in an audit. The good news: a compliant medical bill is a fixed checklist. Get these fields right once and every bill your pharmacy prints is clean.

This is a practical guide, not tax advice. GST rules change — confirm the current position with your CA or the official GST portal before filing.

Mandatory fields on a pharmacy tax invoice

Under GST, a tax invoice for goods must carry a specific set of details. For a chemist shop, that means:

1. Your shop's name, address, and GSTIN.
2. A unique, sequential invoice number for the financial year (no gaps, no duplicates).
3. Invoice date.
4. Customer's name — and, if they're registered and want input credit, their GSTIN and address.
5. Description of each medicine — name, pack, and ideally batch number.
6. HSN code for each item (see below).
7. Quantity and unit.
8. Taxable value per line (price after any discount, before tax).
9. GST rate and amount — split into CGST + SGST, or IGST (see below).
10. Total invoice value, and it's good practice to print the amount in words.
11. Signature of the supplier or an authorised person (a digital signature counts).

HSN codes for medicines

HSN (Harmonised System of Nomenclature) codes classify what you're selling. Most pharmaceutical formulations sit under Chapter 30 — for example, HSN 3004 covers most medicaments sold in measured doses (tablets, capsules, syrups). Whether you must print HSN — and at how many digits — depends on your turnover, so check the current threshold. The simplest approach: store the correct HSN against each product in your catalog once, and let it print automatically on every bill.

GST rates on medicines

Medicines don't all sit at one rate. Broadly you'll encounter:

• 5% — most essential and life-saving medicines.
• 12% — a large share of common formulations.
• 18% — some products and health items.
• Nil — a small list of exempt items.

Because the rate varies by product, the tax should be calculated per line, not as one flat percentage on the bill total. Storing the rate against each product is what makes this reliable.

CGST + SGST vs. IGST

Which tax you charge depends on where the customer is, not what you sell:

• Same state (intra-state) — split the GST into CGST and SGST, half each. A 12% item becomes 6% CGST + 6% SGST.
• Different state (inter-state) — charge a single IGST at the full rate (12%).

For a walk-in retail chemist, almost every sale is intra-state, so you'll mostly print CGST + SGST.

A worked example

Say you sell 10 strips of a 12% medicine at ₹22.00 each (taxable value), same state:

• Taxable value: 10 × ₹22.00 = ₹220.00
• CGST @ 6%: ₹13.20
• SGST @ 6%: ₹13.20
• Line total: ₹246.40

Add each line the same way, and the invoice total is the sum of taxable values plus the sum of CGST and SGST. Do this by hand across a busy counter and mistakes creep in — which is exactly why software should do the maths.

Let the software do it

Every field above is either fixed (your GSTIN, address) or stored against the product (HSN, GST rate). Set it up once and a good billing app assembles a compliant invoice automatically — correct split, sequential numbering, batch on the line. DravyaOS does exactly this, offline, from the keyboard: type the medicine, press Enter, and the GST-compliant line drops in with the maths already done.

Next: if you're still choosing a tool, see our guide to the best free pharmacy billing software in India, or learn how to keep write-offs down with batch & expiry tracking.