Does an optical shop have to print HSN codes on the invoice?

A GST-registered shop under the regular scheme shows HSN or SAC against each line, and the number of digits required depends on your turnover slab as notified. A Bill of Supply carries no tax rate and no tax rows; LensVerge leaves the HSN column off it too. The prescribed particulars are lighter there, so confirm with your CA what your turnover slab requires.

Is GST calculated before or after a discount?

After. The taxable value is the amount left once the discount is applied, and GST is charged on that. Charging tax on the pre-discount price overstates your output tax and overcharges the customer.

What is the difference between a Tax Invoice and a Bill of Supply?

A Tax Invoice is issued by a regular-scheme registered shop: it shows GSTIN, HSN, taxable value and the CGST/SGST or IGST split. A Bill of Supply is issued for exempt supplies and by composition dealers: it charges no GST to the customer, shows no tax rows and no HSN column, and a composition dealer must carry the prescribed declaration on it.

Do I need the customer GSTIN on an optical bill?

Only when the customer is registered and wants input credit — typically a company buying safety eyewear or spectacles for staff. A walk-in retail customer is unregistered, and the invoice is a B2C supply. Capture the GSTIN when it is offered, because adding it after the bill is printed is a credit note exercise.

Do eye tests attract GST?

Eye testing is a healthcare service under SAC 9993 and is exempt. Repair labour is a different matter — it falls under SAC 9987 and is taxable. If you bill both on one document, the exempt line must be shown as exempt rather than silently taxed. Rates as notified; confirm with your CA.

Optical shop GST invoice format

6 min read · Last updated 4 September 2026

An optical bill is unusual: one document can carry a taxable frame, a taxable lens, an exempt eye test and a taxable fitting charge. Getting the format right matters because the invoice is the document your GSTR-1 is built from. Here is exactly what has to be on it, what changes when you are not GST-registered, and a worked example to the paisa.

1. Which document do you issue?

Everything downstream follows from one fact: your registration status. There is no such thing as a shop that issues a Tax Invoice sometimes and a Bill of Supply other times because the bill happened to have no tax on it.

Your status	Document	GST charged to customer
Registered, regular scheme	Tax Invoice	Yes — CGST + SGST or IGST
Registered, composition scheme	Bill of Supply	No — you pay the composition levy yourself
Not registered	Bill of Supply (a plain retail bill)	No

A registered shop that gives a 100% discount, or where a loyalty redemption wipes the bill to zero, still issues a Tax Invoice. The document type comes from your registration, not from whether this particular bill happened to carry tax. This is a genuinely common software bug — a system that decides the title by looking at the tax total will print “Bill of Supply” on a registered shop’s fully-discounted sale.

2. Mandatory fields of a tax invoice

A GST tax invoice is a prescribed document. These are the fields it must carry, in the language of an optical counter:

Your shop name, address and GSTIN. The trade name customers know plus the registered details.
“Tax Invoice” as the document title. Not “Bill”, not “Receipt”, not “Cash Memo”.
A unique, sequential invoice number within the financial year, and the date of issue. Gaps and duplicates are the first thing an assessment looks at.
Customer name, plus address and GSTIN where the customer is registered.
Place of supply — the state, with its code — whenever the supply is inter-state, and in practice worth printing always.
Line-wise description, HSN or SAC, quantity, unit price, discount, and taxable value.
Rate and amount of tax per line or per rate block — CGST and SGST separately for an intra-state sale, IGST for inter-state.
Total invoice value, and whether tax is payable on reverse charge (for a retail optical shop it will normally be “No”).
Signature or digital signature of the supplier or an authorised signatory.

Two practical additions that are not GST requirements but save arguments: the prescription the lenses were made to, and the frame model with its photo. Both belong on the copy the customer keeps.

3. Bill of Supply — what changes

A Bill of Supply is the same document with the tax machinery removed. If you are on the composition scheme or not registered:

The title is “Bill of Supply”, not “Tax Invoice”.
There are no CGST/SGST/IGST rows and no tax rate column.
There is no tax rate column and no tax rows. HSN is not what a Bill of Supply is for, and LensVerge leaves the column off — the prescribed particulars are lighter here, so confirm with your CA what your turnover slab requires.
The totals line reads Net Amount, not “Taxable Amount”.
No GSTIN block for an unregistered shop; a composition dealer shows their GSTIN.

The composition declaration

A composition dealer must carry the prescribed declaration on the face of every Bill of Supply, in words to the effect of: “Composition taxable person, not eligible to collect tax on supplies.” Missing it is one of the most common small-shop defects, and it takes one line of print to fix. Use the current prescribed wording — confirm it with your CA.

4. HSN on every line

An optical shop sells across several HSN heads on the same bill, which is why a generic billing app so often gets it wrong: it lets you set one tax rate for the shop and applies it to everything.

Item	HSN / SAC	GST
Spectacle frames	9003	12%
Sunglasses	9004	12%
Spectacle lenses	9001	12%
Contact lenses	9001 1000	12%
Cases, pouches, boxes	4202	18%
Lens cleaning solution	3402	18%
Repair / fitting labour	9987 (SAC)	18%
Eye test	9993 (SAC)	Exempt

Rates as notified; confirm with your CA before filing. Note the trap in the first two rows: a sunglass is not a separate tax world, it is HSN 9004 while a prescription frame is 9003 — same 12%, different code, and the code is what your GSTR-1 summary is grouped by. Our full HSN and GST reference for optical shops goes through each line in detail.

5. Place of supply and the tax split

For an over-the-counter sale, the place of supply is where the goods are handed over — your shop. That makes almost every optical sale intra-state, and the tax splits into equal halves of CGST and SGST: a 12% frame becomes 6% + 6%.

It changes when you ship. If you courier spectacles to a customer in another state, the place of supply is the delivery address, the sale is inter-state, and the full 12% is charged as IGST instead. The total the customer pays is identical; only the split and the return treatment differ. If you have started shipping orders that came in over WhatsApp, this is the field to get right.

6. A worked frame + lens + fitting bill

A typical dispensing sale: a ₹3,500 frame, a ₹2,200 pair of lenses, a ₹150 fitting charge, and a 10% discount given on the goods. Sold in your own state to an unregistered customer.

Line	HSN/SAC	Amount	Taxable	Tax
Frame	9003	₹3,500.00	₹3,150.00	12% → ₹378.00
Lenses (pair)	9001	₹2,200.00	₹1,980.00	12% → ₹237.60
Fitting charge	9987	₹150.00	₹150.00	18% → ₹27.00

Taxable value ₹5,280.00. Tax ₹642.60, which on an intra-state sale prints as CGST ₹321.30 and SGST ₹321.30. Grand total ₹5,922.60.

Three things this example is showing you. The discount came off before tax on each line. The fitting charge is on a different rate from the goods, so a single shop-wide tax rate would have been wrong. And if the customer had also had an eye test, that line would appear at ₹0 tax as an exempt supply — not quietly folded into the frame price, which is how exempt revenue ends up misreported.

7. Copies, numbering and cancellations

For a supply of goods, an invoice is prepared in triplicate — original for the recipient, duplicate for the transporter, triplicate for the supplier — and each copy is marked as such. For a retail counter sale where nothing is transported, the practical output is the customer copy and your own record.

Numbering must be sequential and unique within the financial year. Do not restart the series mid-year, do not keep two parallel books (a thermal roll and a PDF series) with overlapping numbers, and do not delete a bill.

Cancel, never erase. If a sale is reversed, void the invoice so the number stays in the series with a visible cancelled status and a trail of who did it and when. If the period has already been filed, the correction is a credit note rather than a quiet edit. Software that lets a staff member delete a bill outright is not saving you trouble — it is manufacturing it. We cover this and four other traps in optical shop billing mistakes.

LensVerge issues the right document automatically. Your shop is set to regular, composition or unregistered once, and every surface — screen, thermal receipt, A4 and A5 PDF, and the WhatsApp link — follows it: Tax Invoice with HSN and the correct split, or Bill of Supply with the composition declaration and no HSN column. Voids keep the number and stamp the paper CANCELLED. See the billing software or start a 14-day free trial.