New GSTR-1 and GSTR-3B Formats From April 2027: What the Draft Changes, and What to Tell CBIC Before 30 November

The GST Council's 57th meeting on 8 October 2026 approved what CBIC calls an alternate mechanism for amending tax liability and input tax credit inside the return system. The draft rules, forms and a circular went up on MyGov for public comment from 1 to 30 November 2026, and the changes are proposed to apply from the April 2027 return period. Returns up to March 2027 stay on the current forms.

The idea is simple to state. GSTR-3B should stop being a place where numbers are typed in. Outward liability should come from GSTR-1, as corrected through GSTR-1A or IFF, and normal input tax credit should come from GSTR-2B, as shaped through the Invoice Management System. If a figure is wrong, you fix it at the source, not in GSTR-3B.

Why CBIC is doing this

Most system-generated GST intimations come from two comparisons: GSTR-1 against GSTR-3B for liability (DRC-01B, Rule 88C) and GSTR-2B against GSTR-3B for ITC (DRC-01C, Rule 88D). Both exist because GSTR-3B, although it is auto-populated, can still be edited before filing. Every edit is a potential mismatch. The tools to correct data at the source, such as GSTR-1A, IMS and the credit reversal and reclaim statement, already exist, but apart from GSTR-1A most of them are portal features rather than rules. The draft puts them into the CGST Rules and makes them the only route.

The rules that change the workflow

GSTR-1 and GSTR-1A

GSTR-1 gets more granular so that the portal can place every figure in the right GSTR-3B table without guesswork. The notable changes in the draft:

• Table 4 (B2B) is split further. Supplies made through an e-commerce operator that collects TCS get their own row (4E), separate from regular, reverse charge and SEZ supplies.
• Tables 5 and 7 (B2C) separate e-commerce TCS supplies from direct ones, and Table 7 splits intra-State B2C supplies from inter-State B2C supplies up to ₹1 lakh, with place of supply.
• Table 9 (amendments, credit and debit notes) gains a drop-down saying which original table an amendment relates to, so GSTR-3B can reduce the right line.
• Table 11 (advances) lets an advance be tagged to the table of the eventual supply.
• Table 12 (HSN) is split into supplies to registered and unregistered persons, with a new Table 12A to amend an earlier period's HSN summary.
• A new Table 8AA allows nil-rated, exempt and non-GST supplies of earlier periods to be amended.
• Suppliers may voluntarily link credit and debit notes to the original invoices.

GSTR-1A becomes the main correction tool. Today it only amends the current period. The draft lets it amend or add details for the current period or an earlier one, subject to the Section 37(3) time limit, and allows a wrong recipient GSTIN to be corrected. It opens after the GSTR-1 due date or the actual GSTR-1 filing date, whichever is later, and stays open until GSTR-3B is filed. It remains optional and carries no late fee. Supplies added through GSTR-1A reach the recipient's next open GSTR-2B.

GSTR-2B, IMS and GSTR-3B

• Draft GSTR-2B is generated on the 14th of the following month, and only if the previous period's GSTR-3B has been filed. A taxpayer who is behind cannot get the next GSTR-2B until they catch up.
• A revised GSTR-2B can be requested after IMS actions taken post-generation, before GSTR-3B is filed.
• A new GSTR-2B Table 6 lists invoices and credit notes rejected in IMS, so rejected documents are visible rather than simply absent.
• If the recipient rejects a credit note, the tax goes back onto the supplier's liability in the next return, with interest from the due date of the original period.
• GSTR-3B gets a new Table 4(AA) for ITC reclaimed after an earlier temporary reversal, instead of routing reclaims through 4(A)(5) and 4(D)(1). The reclaim cannot exceed the PMT-02A balance.
• A new PMT-10 lets a taxpayer correct an excess permanent reversal made in Table 4(B)(1) of an earlier return, within the Section 39(9) time limit.

DRC-03 Part B: fixing the double-liability problem

Today, when a supplier pays tax through DRC-03 after an audit or scrutiny and then reports the related invoice in GSTR-1 so the buyer can claim credit, the same tax lands in GSTR-3B again. The usual workaround is to edit GSTR-3B down, which creates the very mismatch the system flags. The draft adds a Part B to DRC-03, to be filed within seven days of the Part A payment, listing the registered recipients and invoices. Part B populates GSTR-1 directly, cannot be edited there, and does not add the tax to GSTR-3B a second time. The buyer gets the credit through GSTR-2B.

Comments worth sending before 30 November

The consultation is the only point at which practitioners can shape the operational detail. A comment is more useful when it describes a concrete situation the draft does not handle. Areas that deserve scrutiny:

1. The GSTR-2B gate. Making GSTR-2B depend on the previous GSTR-3B being filed can lock a taxpayer who missed one month out of credit for every month after it. Ask for a catch-up path.
2. GSTR-1A timing for quarterly filers. Check how the window works for QRMP taxpayers who also file IFF, and whether a correction found after GSTR-3B is filed must wait a full period.
3. Deemed acceptance in IMS. Silence becomes acceptance at GSTR-3B filing. Ask whether there will be a warning before deemed acceptance, especially for credit notes that reduce ITC.
4. Transition. Ask how amendments made after April 2027 to invoices of earlier periods will be reported, and how opening balances for PMT-02A and PMT-02B will be set.
5. The Table 9 drop-down. Mapping every amendment to its original table is extra work on high-volume returns. Ask for bulk upload and API support.
6. DRC-03 Part B's seven-day window. Audit and scrutiny payments often cover many invoices across many recipients. Ask whether seven days is realistic.

Practitioners report that submitted suggestions cannot be edited, so draft the comment offline and submit it once.

What to change in your practice now

April 2027 is close enough that habits formed this year will carry over. Three changes are worth making early. Stop treating GSTR-3B as the place to fix errors, and correct liability through GSTR-1A today wherever the current rules allow. Clear IMS every month rather than at the deadline, because inaction already means deemed acceptance, and the draft writes that into the rules. And keep a monthly GSTR-1 versus GSTR-3B comparison by tax head for every client, because if the draft is notified as proposed, any difference you cannot explain from April 2027 will be one you are no longer allowed to make.