What is Form GSTR-1A and when should I file it?

Form GSTR-1A is an optional form that opens after filing GSTR-1 but closes before filing GSTR-3B for the same month. It allows suppliers to add missed sales bills or correct invoice errors in real-time.

What is the key difference between GSTR-1A and GSTR-1 Amendment Tables?

GSTR-1A corrects errors in the CURRENT tax period (before GSTR-3B). GSTR-1 Amendment Tables (Table 9A) correct errors from PREVIOUS tax periods in a future month's GSTR-1.

Is there any late fee for not filing Form GSTR-1A?

No. GSTR-1A is an optional facility. If you have no current-month sales corrections to make, you can skip GSTR-1A entirely and proceed directly to filing GSTR-3B.

How do I update sales voucher effective dates in Tally Prime for GSTR-1A?

Open the sales voucher in Tally Prime, press Ctrl+I (More Details), select 'GST Return Effective Date', update the date, and save with Ctrl+A.

How to File GSTR-1A for Invoice Amendments & Corrections (2026)

Quick Summary: What Is Form GSTR-1A and How Does It Work?

Form GSTR-1A is an optional bridge form available on the GST portal after filing GSTR-1 but before filing GSTR-3B for the same tax period. It enables suppliers to add missed invoices or amend tax values, ensuring buyers receive correct ITC in their IMS/GSTR-2B before GSTR-3B liability is locked.

Window of Operation: Opens after GSTR-1 filing (11th-13th) and closes when GSTR-3B is filed (20th).
Buyer Benefit: Passes corrected ITC to buyer's IMS dashboard before monthly 2B crystallization.
Zero Late Fees: Completely optional; no penalty for skipping if no same-month edits are needed.
Tally Workflow: Use Ctrl+I (GST Return Effective Date) in Tally Prime to align amendment dates.

1. GSTR-1A vs GSTR-1 Amendment Tables Comparison

Understanding when to use Form GSTR-1A versus standard GSTR-1 Amendment Tables is crucial for GST compliance:

Feature Parameter	Form GSTR-1A (Same-Month Bridge)	GSTR-1 Amendment Tables (Past-Period)
Target Period	CURRENT tax period (Same month)	PAST tax periods (Previous months)
Filing Window	After GSTR-1 filing, before GSTR-3B filing	During subsequent month's GSTR-1 filing
GSTR-3B Impact	Auto-populates corrected liability in CURRENT 3B	Adjusts liability in SUBSEQUENT 3B
Status	Optional facility (Zero late fee)	Standard mandatory GSTR-1 table

2. Step-by-Step Portal Filing Guide for GSTR-1A

Log in to GST Portal > Services > Returns > Returns Dashboard.
Select financial year and current tax period. Click on Form GSTR-1A tile.
Select the relevant table to amend: Table 4 (B2B Sales), Table 9A (Amended Invoices), or Table 12 (HSN Summary).
Add missing invoices or modify tax amounts. Click Save & Generate Summary.
Submit with EVC or DSC before filing GSTR-3B.

Eliminate Sales & Purchase Discrepancies in Tally

Auto-post verified purchase vouchers to prevent vendor GSTR-1A amendments.

When suppliers make typing mistakes in GSTR-1, you must ask them to file GSTR-1A. Automating your own purchase vouchers ensures your incoming bills match vendor filings perfectly.

TrulyInvoice AI Automation: Upload supplier PDF bills or WhatsApp scans. AI auto-extracts line items and posts F9 Purchase Vouchers directly to Tally Prime in 15 seconds via Port 9000 local sync.