Understanding GSTR-1A: Key Aspects, Structure, and Compliance Deadlines
GSTR-1A is a crucial GST form enabling taxpayers to amend previously filed sales details in GSTR-1 before submitting GSTR-3B. Reintroduced in 2024, it allows corrections for errors or omissions within the same tax period, but only once. This guide provides an in-depth look at its purpose, operational mechanism, filing deadlines, and the comprehensive details required across its 15 tables, reflecting recent updates and compliance requirements.
Understanding GSTR-1A: Key Aspects, Structure, and Compliance Deadlines
GSTR-1A is a document designed to incorporate modifications to sales invoices initially reported in GSTR-1. After a period of suspension following the 2017 GST implementation, this form was reintroduced in 2024. This article explores the meaning, purpose, due dates, required details, and format of GSTR-1A.
Recent Developments and Updates
June 7th, 2025
- The GSTN, through an advisory, announced the implementation of hard-locking for auto-populated sales liability values in GSTR-3B, effective from the July 2025 tax period (filed in August 2025). This measure prevents taxpayers from manually altering Table 3 values in GSTR-3B, which are automatically derived from GSTR-1, GSTR-1A, or IFF. Suppliers must promptly address any documents rejected by their B2B buyers via the Invoice Management System (IMS) using GSTR-1A.
- Another advisory from GSTN established a three-year deadline for filing GSTR-1, GSTR-3B, GSTR-4, GSTR-5, GSTR-5A, GSTR-6, GSTR-7, GSTR-8, and GSTR-9, commencing from their respective due dates. This change will be active on the GST portal from the July 2025 tax period.
April 11th, 2025
Phase-III for Table 12 of GSTR-1 and GSTR-1A was implemented by the GST Network starting from the April 2025 return period. Consequently, B2B and B2C supplies must be categorized separately for HSN-wise reporting in Table-12 of GSTR-1. Manual entry of HSN codes is no longer permitted; taxpayers must select from a dropdown list as per the advisory issued on April 11th, 2025.
January 9th, 2025
GSTN issued an advisory concerning the mandatory reporting of HSN codes in GSTR-1 and GSTR-1A.
- Phase 3 for HSN code reporting in Table 12 of GSTR-1 and GSTR-1A is being rolled out from the January 2025 return period on the GST portal.
- In this phase, manual HSN entry has been replaced with a dropdown selection for accurate HSN codes.
- A custom description from the HSN master will automatically populate a new field called