Phase-III Implementation of Table-12 in GSTR-1/GSTR-1A – Effective April 2025

HSN Changes from April 2025 – Everything You Must Know

Introduction:

The GSTN has rolled out Phase-III changes to Table-12 of GSTR-1 and GSTR-1A, effective from the April 2025 tax period. These changes aim to streamline HSN-wise reporting, enhance data accuracy, and prevent duplication.

In this article, we decode all the updates, explain their implications, and help you stay compliant.

What is Table-12 of GSTR-1/GSTR-1A?

Table-12 is used for reporting HSN-wise summary of outward supplies. It captures the details of outward supplies based on the Harmonized System of Nomenclature (HSN) codes.

With Phase-III, this table sees major enhancements for better validation and structured compliance.

Key Changes in Phase-III Implementation:

1. B2B and B2C Split Introduced:

Table-12 is now split into two distinct sections:
- B2B (Business to Business)
- B2C (Business to Consumer)
HSN summary needs to be reported separately for each category.
This helps in accurate cross-checking with the respective sections of the return.

2. No Manual HSN Entry Allowed:

Manual HSN input is disabled.
You must select the HSN code from a system-generated dropdown list.
This ensures:
- Accuracy of codes
- Avoidance of typographical errors
- Easier validation against standard HSNs

3. Delta-Based Reporting for Amendments:

For amendments to already filed data, taxpayers must now report only the difference (delta) between original and revised values.
Full revised amounts should not be reported.
This prevents duplication and maintains a clean audit trail.

HSN Cross-Validation Rules:

To ensure consistency and avoid mismatches, the system will validate the values in Table-12 against other tables of GSTR-1/GSTR-1A as per the supply type:

For B2B Supplies:

Table-12 values will be validated against:

Table 4A: B2B Invoices
Table 4B: Supplies attracting reverse charge
Table 6B: SEZ supplies with payment of tax
Table 6C: SEZ supplies without payment of tax
Table 8: Nil-rated, exempt, and non-GST (registered)
Tables 9A, 9B, 9C: Amendments (registered)
Table 15, 15A: Outward Supplies attracting TCS/TDS (registered)

For B2C Supplies: