The GSTN has issued an important Advisory relating Implementation of Phase III for mentioning of HSN codes in GSTR-1 & GSTR 1A. 

Key Changes Effective January 2025:

1. Replacement of Manual HSN Entry

• Manual entry of HSN codes in Table 12 is discontinued.
• Taxpayers are now required to select the correct HSN from a dropdown menu provided in the system.

2. Bifurcation of Table 12 into two separate tabs:

• B2B Supplies: Reporting of supplies to registered persons.
• B2C Supplies: Reporting of supplies to unregistered persons.

3. Validation of Values and Tax Amounts:

• New validation checks introduced for Value of supplies, Tax amounts involved.
• in initial period these validations have been kept in warning mode only, which means failing the validation will not be a blocker for filling of GSTR-1& 1A.

The Complete Advisory relating to Reporting of HSN codes in Table 12 of GSTR-1/1A can be accessed at https://tutorial.gst.gov.in/downloads/news/advisory_on_hsn_validation_08_01_25.pdf

Source: GSTN