How Many Digits of HSN Code Do You Need on a GST Invoice? (4, 6 or 8 Digits by Turnover)

If you run a shop in India, you have probably seen HSN codes written as 4 digits on one supplier's bill, 6 digits on another and 8 digits on a third. So which one is right for your own invoices? The answer depends mainly on one number: your business's aggregate turnover in the previous financial year.

This guide explains the HSN code digits required on invoice under GST, how to work out which rule applies to you, and how to set up your billing so you never have to think about it at the counter.

Quick Answer: The HSN Digit Rule by Turnover

Since 1 April 2021 (Notification No. 78/2020 - Central Tax), the minimum number of HSN digits you must show on a tax invoice is:

The same digit rule applies to SAC codes if you also bill for services, such as repairs or installation.

A few points shop owners often miss:

• The rule is based on last year's turnover, not the current year. If you cross ₹5 crore this year, the 6-digit rule applies from the next financial year.
• "Aggregate turnover" is calculated on a PAN basis, so it includes all GSTINs registered under the same PAN across states.
• These are minimums. You are always allowed to print more digits than required.

What the 4, 6 and 8 Digits Actually Mean

HSN (Harmonised System of Nomenclature) is a global product classification system. Each extra pair of digits narrows the product down further:

• 2 digits (Chapter): the broad category, for example 94 for furniture and lighting.
• 4 digits (Heading): a product group, for example 9403 for other furniture.
• 6 digits (Sub-heading): a more specific type, for example 940360 for other wooden furniture. The first 6 digits are the same in every country that uses HSN.
• 8 digits (Tariff item): India's own further breakdown, used mainly in the Customs Tariff for imports and exports.

So a 4-digit code is not "wrong" compared to an 8-digit one. It is simply less detailed, and GST law allows smaller businesses to use the shorter version.

When Do You Need 8 Digits?

For most domestic retail sales, GST does not require the full 8-digit code. You will mostly need 8 digits in these situations:

• Imports and exports: customs documents such as the shipping bill and bill of entry use the 8-digit tariff item.
• Certain notified chemicals: the government has notified a short list of chemical items for which the full 8-digit code must be reported regardless of turnover. If you sell industrial chemicals, check this with your accountant.
• When your supplier already uses it: many wholesalers print 8 digits. You can copy that code into your item master as is, since printing more digits than the minimum is always allowed.

If your shop sells ordinary goods like electronics, furniture, gifts or groceries within India, 4 or 6 digits will cover you.

Why Using More Digits Can Still Be a Good Idea

Even if your turnover is under ₹5 crore, there are practical reasons to store 6 or 8 digit codes in your system:

1. Correct GST rate. Two products under the same 4-digit heading can sometimes carry different GST rates. The longer code makes it clear which rate applies.
2. Fewer questions from B2B buyers. Larger buyers who fall under the 6-digit rule often prefer detailed codes to match their own purchase records.
3. Future-proofing. If your business grows past ₹5 crore, your item master is already ready and nothing needs to be re-entered.
4. Matching supplier bills. It is easier to reconcile purchases when your codes match what appears on your supplier's invoice.

HSN Digits in GSTR-1 Returns

The digit rule also applies to the HSN-wise summary you report in Table 12 of GSTR-1. Businesses with turnover up to ₹5 crore report at least 4 digits, and those above ₹5 crore report at least 6 digits. The GST portal now validates these codes more strictly, with HSN codes selected from a dropdown list and B2B and B2C supplies reported separately, so codes that do not match the official list can cause trouble when filing.

This is one more reason to keep HSN codes accurate in your billing software: whatever you print on invoices flows straight into the summary your accountant files.

What Happens If You Get It Wrong?

Not showing the required HSN digits makes the invoice incomplete. There is no specific penalty just for HSN codes, but the general penalty under Section 125 of the CGST Act can apply, which is up to ₹25,000 under CGST plus ₹25,000 under SGST. More commonly, the real cost is practical: B2B customers may ask you to reissue invoices, and mismatches can create headaches during return filing or an audit.

How to Set This Up Once and Forget It

The easiest way to stay compliant is to store the HSN code against each product rather than typing it on every bill:

1. Find the right code for each product using our free HSN Code Finder, or refer to our HSN Code List with GST Rates for Common Retail Shop Products.
2. Save it in your item master, along with the GST rate. Our guide on How to Set Up HSN Codes in Your Item Master and Sales Account walks through this step by step.
3. Store at least 6 digits where possible, even if you only need 4 today.
4. Let your billing software print it automatically on every invoice. Trayvo pulls the HSN code and GST rate from your item master, so staff at the counter never have to remember them.

For the full list of details a valid tax invoice must carry, see our post on GST Invoice Rules in India: Mandatory Fields and Sample.

Frequently Asked Questions

Is HSN code mandatory on B2C invoices?

If your aggregate turnover in the previous financial year was up to ₹5 crore, HSN codes are optional on B2C invoices. If it was more than ₹5 crore, you must show at least 6 digits on every invoice, including B2C.

Can I print 8 digits even if I only need 4?

Yes. The rule sets a minimum, not a maximum. Printing 6 or 8 digits is always acceptable and often makes the GST rate clearer.

How is aggregate turnover calculated for the HSN rule?

It is the total value of all taxable, exempt, export and inter-state supplies made under the same PAN across India in the previous financial year, excluding GST itself and inward supplies taxed under reverse charge.

Do the same digit rules apply to SAC codes for services?

Yes. SAC codes follow the same turnover thresholds, so a business up to ₹5 crore shows 4 digits on B2B invoices and a business above ₹5 crore shows 6 digits on all invoices.

What if my turnover crosses ₹5 crore in the middle of the year?

The digit requirement is based on the previous financial year's turnover. You can continue with the 4-digit rule for the rest of the current year, but you must switch to 6 digits from the start of the next financial year.