Answer

1. F

   Facts

   From the July 2025 tax period, the liability auto-filled in GSTR-3B from GSTR-1, GSTR-1A and IFF is not editable. Errors in outward supplies must be corrected through GSTR-1A before filing GSTR-3B. Once GSTR-3B is filed, it cannot be revised.

2. P

   Provisions and law

   • Sec 37, CGST Act 2017Details of outward supplies to be furnished in GSTR-1
   • Sec 39(9), CGST Act 2017Errors in a return are corrected in a later return, within the time limit
   • Rule 61, CGST Rules 2017Form and manner of GSTR-3B; monthly filers by the 20th of the next month
3. A

   Analysis

   If you reported an invoice of ₹5,00,000 as ₹50,00,000 in GSTR-1, GSTR-3B will show tax on the wrong figure and you cannot type it down. The fix is to file GSTR-1A for the same month with the corrected invoice, which then updates GSTR-3B. If GSTR-3B is already filed, the excess can only be adjusted through amendments in a later GSTR-1 and the next GSTR-3B, within the time limits of Sec 39(9) and Sec 34.

4. C

   Conclusion

   1. 1Compare the GSTR-3B auto-filled figures with your sales register before you file
   2. 2If GSTR-1 has an error, open GSTR-1A for the same period and correct the invoice
   3. 3Check that GSTR-3B now shows the corrected liability
   4. 4File GSTR-3B and keep a note of the correction

Never file GSTR-3B first and plan to correct later; the wrong liability becomes final.

General guidance from TaxSavvy’s library of money processes. Laws change; your Savvy confirms the answer on your exact case before anything is filed.