HSN codes in GSTR-1: Table 12 dropdowns, B2B/B2C split and the now-mandatory Table 13

Since Notification No. 78/2020-Central Tax (15 October 2020), businesses must report 4-digit or 6-digit HSN codes in Table 12 of GSTR-1, depending on their turnover in the previous year. The rules have been brought in in phases, and Phase 3 is now live.

What Phase 3 changed (from the May 2025 return period)

1. Choose HSN from a dropdown. Typing HSN codes by hand has been replaced by picking the correct code from a list, which reduces invalid codes.
2. Table 12 is split into B2B and B2C tabs. Supplies to registered and to unregistered buyers are reported separately.
3. Value and tax checks compare Table 12 against your supplies. They started in warning mode (not blocking filing) at first.
4. Table 13 (documents issued) is now mandatory in GSTR-1 and GSTR-1A, so you must report the series and count of invoices, credit notes and other documents issued.

How to stay compliant

• Keep an item master with the correct HSN in your billing software, since that's where accuracy starts.
• Make sure HSN totals match your B2B and B2C sales figures.
• Track invoice and credit note number series so Table 13 is easy to fill.
• Look up HSN codes and current GST rates quickly in the FinGST app.

Official source

• GSTN advisory: HSN in Table 12 and documents in Table 13 (PDF)
• GSTN advisories