Omitted sales shown in GSTR-1 Table 14 but not in Table 7. How to fix in next return without

• GSTR-1 (Sept): Use Table 10 to amend August's B2C (Table 7) figures upwards by the missed ₹4 lakh. Do not duplicate the entries in Table 14 for September.

• GSTR-3B (Sept): Pay the pending tax liability (₹71,000) in Table 3.1 and declare the interest calculated @ 18% p.a. in Table 5.1.

1. Interest period: These sales belong to July 2025 (original due date 20 Aug 2025). If I amend through Table 10 of the Aug 2026 return, I think the portal will calculate interest only from the Aug 2026 due date. Should I edit the interest in Table 5.1 myself and pay it from 21 Aug 2025 (about 18% p.a. on the tax, around ₹73,400)?
2. Financial year: These sales are of FY 2025-26, but they will show in the FY 2026-27 return through Table 10. Is that acceptable, given the 30 Nov 2026 limit? Do I need to show it separately anywhere for FY 2025-26 (for example in GSTR-9, if applicable)?

One more detail: the actual taxable value is about ₹4.09 lakh and tax about ₹73,400 (B2C, Amazon and Flipkart). July 2025 B2B was already in Table 4A of the Aug return, so I am not adding it again.

Thanks again for your help.

On the interest question: it runs from the original due date, not from the month you amend.

The July 2025 GSTR-3B was due on 20 Aug 2025, so interest u/s 50 at 18% p.a. runs from 21 Aug 2025 till the date you actually pay. If the portal auto-calculates from the later date, the extra interest in Table 5.1 of the September 3B should be declared yourself. Under-paying interest is a common notice trigger.

Two more points:
- Interest is on the tax paid in cash. If you had unused ITC in the ledger during that period, Rule 88B limits interest to the net cash portion.
- Late fee u/s 47 may also apply for the period. Check it.

For the financial year point: yes, the supply is still of FY 2025-26, but the correction goes in the return of the month you make it. A supplier cannot make amendments for a financial year after 30 November following the end of that year (Section 37(3)) or the annual return date, whichever is earlier. For FY 2025-26 that is 30 Nov 2026, so you are within time. Also mention it in GSTR-9 for FY 2025-26 if that is filed after you have corrected.

This [GST late fee and interest guide](https://taxgarden.in/blog/gst-late-fee-interest-penalty-gstr-3b-gstr-1-gstr-9-guide) has the Section 50 and Rule 88B examples.

Human checks before posting (do NOT paste this part): (1) UNVERIFIED: Table 10/14 handling for e-commerce supplies and whether portal lets Table 5.1 interest be edited; confirm on gst.gov.in before posting or drop that sentence. (2) Section 37(3) cutoff and Rule 88B come from CGST Act/Rules on cbic.gov.in, recheck the wording. (3) Whether GSTR-9 reporting is required: verify against GSTR-9 instructions. (4) Plain text only for CAclubindia; the 1 expert reply (Aashok Kumar Sharma) already said Table 10 and 18%, do not contradict, add the date point.

adding a caution on the table 14 point, since i am not fully sure how the portal treats this. table 14 is the eco-wise figure of supplies made through each eco, and it is supposed to tie to what the eco reports in its gstr-8. it does not itself carry the liability, that comes from table 4/7 (and 10 for amendments). since the july 2025 value is already sitting in aug's table 14 and you will add the same sale in sept's table 7, i would be careful not to show the same 4 lakh again in sept's table 14 unless you amend aug's through 14a, or the eco-wise totals may not match gstr-8. i am not certain which route the portal accepts, so please check with your consultant.

as for the 3b breakup table that cannot be edited: nothing to fix there, pay the extra tax and interest through the sept 3b and keep a note of the working. the interest runs from the original due date of july 2025 (20 aug 2025), as the other reply said.