HSN Code 8421: Product Classification, GST Rate & Business Filing Guide

HSN Code 8421 belongs to Chapter 84 of the Harmonised System of Nomenclature, which covers nuclear reactors, boilers, machinery, and mechanical appliances. This code sits under Section XVI of the HSN schedule, covering machinery and mechanical appliances, electrical equipment, and parts thereof. It is highly relevant to manufacturers, traders, distributors and importers across industries such as pharmaceuticals, food processing, automotive, FMCG, water treatment and industrial equipment.

Which goods are covered under HSN Code 8421?

HSN 8421 is broken into specific sub-headings based on the type of equipment. Here is the breakdown:

What GST rate applies to HSN Code 8421?

After the GST rate rationalisation announced in the 56th GST Council meeting held on 3 September 2025, effective from 22 September 2025, there was no specific notified reduction or revision for HSN 8421 in the published HSN-wise rate schedule. Accordingly, HSN Code 8421 continues to attract 18% GST in most cases under the revised GST framework. This rate applies to the supply of both imported and domestically manufactured machinery falling under this heading, unless a separate exemption notification or concessional entry specifically covers a product under 8421.

What are the GST filing requirements for HSN 8421?

Businesses dealing in products classified under HSN 8421 need to comply with several GST return and invoicing requirements detailed below.

1. GSTR-1

GSTR-1 is the monthly or quarterly return used to report all outward taxable supplies made during a tax period.

For businesses supplying HSN 8421 products, outward supplies are reported in:

• Table 4 for inter-state supplies made to registered persons
• Table 5 for inter-state supplies made to unregistered persons
• Table 7 for intra-state taxable supplies
• Table 12 must include an HSN-wise summary of outward supplies, along with the taxable value, GST rate, IGST, CGST and SGST.

From April 2025, Table 12 is divided into separate B2B and B2C sections. Taxpayers must report HSN-wise details separately under each category.

Due dates:

• Monthly filers with aggregate annual turnover above ₹5 crore: 11th of the following month
• Quarterly filers under QRMP with turnover up to ₹5 crore: 13th of the month following the quarter

2. GSTR-3B

GSTR-3B is the summary self-assessment return where taxpayers declare outward supplies, inward supplies, input tax credit claimed and tax payable.

For HSN 8421 businesses:

• Total taxable outward supplies are reported in Table 3.1
• Eligible input tax credit (ITC) on purchases such as raw materials, components, capital goods and input services is claimed in Table 4

From January 2026, GSTN has strengthened ITC validation checks. If the ITC claimed in GSTR-3B exceeds the eligible amount appearing in GSTR-2B, filing may be restricted until reconciliation is completed.

Due dates:

• Taxpayers with turnover above ₹5 crore: 20th of the following month
• Quarterly Return, Monthly Payment  (QRMP) taxpayers: 22nd or 24th of the month following the quarter, depending on the state category

3. GSTR-2B

GSTR-2B is an auto-generated and static input tax credit statement made available on the 14th of every month.

For businesses purchasing HSN 8421 goods:

• ITC can generally be claimed only when the purchase invoice appears in GSTR-2B
• This means the supplier should have filed GSTR-1 or Invoice Furnishing Facility (IFF), and the corresponding return details should be reflected in the GST system

From October 2025, under the Invoice Management System (IMS), imported goods will be processed separately. Businesses should review both GSTR-2B and the IMS import section to verify the complete ITC position.

Also, under Rule 37A, if a supplier does not file GSTR-3B by 30 September 2026 for FY 2025–26, the recipient may be required to reverse the ITC by 30 November 2026. The credit can be reclaimed once the supplier files the pending return.

4. GSTR-9

GSTR-9 is the annual return that consolidates all GST transactions reported during the financial year.

For HSN 8421 dealers:

• HSN-wise outward supply details are reported in Table 17
• This disclosure is mandatory for taxpayers with turnover above ₹5 crore and optional for certain others based on applicable rules
• Turnover, tax paid and ITC figures should match the data reported in GSTR-1 and GSTR-3B

Due date: 31 December following the end of the relevant financial year.

From 1 January 2026, late fees for delayed GSTR-9 filing are applied automatically from the next day after the due date. GST returns pending beyond three years cannot be filed, which may also lead to permanent loss of eligible ITC.

5. GSTR-9C

Businesses with aggregate annual turnover exceeding ₹5 crore are required to file GSTR-9C along with GSTR-9.

This is a reconciliation statement that compares financial statements with GST returns filed during the year. It is now self-certified by the taxpayer, and separate CA certification is no longer mandatory.

6. E-invoice (IRN generation)

E-invoicing applies to B2B transactions for businesses crossing the prescribed turnover threshold.

For HSN 8421 transactions:

• Each B2B invoice must be uploaded to the Invoice Registration Portal (IRP)
• An Invoice Reference Number (IRN) must be generated before the invoice is considered valid under e-invoicing rules

From 1 April 2025, businesses with an annual turnover of ₹10 crore or more must upload invoices to the IRP within 30 days from the invoice date. The portal may reject delayed uploads beyond this period.

ITC on HSN 8421 purchases

Businesses engaged in products under HSN 8421 for their taxable activities are eligible to claim ITC on such purchases. Here are some conditions that must be met:

• The goods must be used for business purposes in connection with taxable supplies
• The supplier must have filed their GSTR-1, and the invoice must appear in the buyer's GSTR-2B
• The supplier must have paid the corresponding GST (otherwise, ITC must be reversed under Rule 37A)
• The buyer must hold a valid tax invoice with the correct HSN code, GSTIN, and GST amount
• The goods should not be used for personal consumption or for making exempt supplies

Note: When HSN 8421 machinery is purchased as a capital good (for use in manufacturing or industrial processes), the full ITC is available in the year of purchase itself, unlike accounting depreciation, which is spread over years. However, if depreciation on the GST component is claimed under income tax, the corresponding ITC cannot be availed.

Conclusion

HSN 8421 directly affects pricing, vendor coordination, cash flow planning and how smoothly your GST compliance runs throughout the year. A small mismatch can create unnecessary follow-ups, delayed credits or reporting gaps later. Building a routine around invoice checks, purchase reconciliation and timely return review can save both time and effort. 

Using accounting software like TallyPrime can make this process easier by keeping HSN reporting, tax calculation and compliance tracking organised in one place as your business scales.