GST Notifications from 1st April 2023

GST Notifications from 1st April 2023: What Changed, What Still Applies, and What to Do in FY 2026-27

From 1 April 2023, CBIC simultaneously activated six significant GST notification packages: e-invoicing became mandatory for taxpayers above ₹5 crore aggregate turnover, six-digit HSN codes became compulsory in B2B invoices above the same threshold, sequential return filing was enforced at portal level, and three concurrent amnesty windows opened for GSTR-4, GSTR-9 and GSTR-10 non-filers. Three years later in FY 2026-27, each of these changes has either been deepened or directly shapes the audit and notice landscape. This guide walks through each notification, the numbers that matter, and exactly what you must do now.

Why 1 April 2023 Was a Compliance Reset Point

CBIC has historically used 1 April as the anchor date for major structural GST changes, and 2023 was particularly dense. Several notifications announced in late February and March 2023 all became effective simultaneously on 1 April. The result was a concurrent shift across four dimensions:

• Invoicing infrastructure — e-invoicing threshold cut from ₹10 crore to ₹5 crore
• Tax data quality — HSN codes at six digits mandated for larger taxpayers
• Return sequencing discipline — sequential GSTR-1 and GSTR-3B filing enforced at the portal
• Dispute backlog clearance — three amnesty schemes opening on the same date

What makes this date significant in 2026 is that each change became a reference point for GSTN analytics. Taxpayers who missed the transition have accumulated late fees, ITC mismatches and DRC-01 / DRC-01C notices. Understanding the original notification helps you trace the root cause of today's compliance problems and address them correctly — rather than treating each notice as a fresh event.

E-Invoicing Threshold Cut to ₹5 Crore: The Notification and Its Consequences

Notification No. 10/2023 – Central Tax, dated 10.03.2023, effective 01.04.2023, reduced the e-invoicing threshold from ₹10 crore to ₹5 crore aggregate turnover in any preceding financial year. This notification amended Notification No. 13/2020 – Central Tax, the original e-invoicing enablement notification.

Who falls in? Understanding aggregate turnover correctly

Aggregate turnover for e-invoicing purposes is calculated at the PAN level, not the GSTIN level. It includes all taxable supplies, exempt supplies, exports and inter-state supplies across every GSTIN registered under the same PAN. A business with ₹4.2 crore in Maharashtra and ₹1.1 crore in Karnataka crosses ₹5 crore on PAN aggregation — and every GSTIN under that PAN with B2B outward supplies must generate e-invoices, not just the one that crossed the state threshold.

Supplies excluded from aggregate turnover for this purpose: inward supplies taxable under reverse charge mechanism (where you are the recipient, not the supplier). Do not include these when self-checking your threshold.

What e-invoicing mandatory actually requires, step by step

E-invoicing is not simply uploading a PDF or generating a JSON. The legally required sequence is:

1. Raise the invoice in your accounting or billing software (Tally, Busy, SAP, Zoho Books, or equivalent)
2. Push the JSON payload to the Invoice Registration Portal (IRP) — via API, direct upload or through a GST Suvidha Provider (GSP)
3. IRP validates the invoice against schema rules and the supplier's GSTN status
4. IRP assigns an Invoice Reference Number (IRN) — a 64-character SHA-256 hash unique to each invoice
5. IRP returns a digitally signed JSON and a QR code containing key invoice fields
6. Print the QR code and IRN on the physical or PDF invoice before it reaches the buyer
7. The IRN-tagged invoice auto-populates into your GSTR-1, Table 4A (B2B supplies)

The critical legal point: if you issue an invoice to a GST-registered buyer without going through IRP when e-invoicing is mandatory for you, the buyer cannot claim Input Tax Credit on that invoice — even if you later report it in GSTR-1. The IRP flow is the statutory trigger for ITC eligibility on the recipient side. This is not a technicality; it is the explicit position under Rule 48(4) read with Rule 36 of the CGST Rules.

Credit notes, debit notes and, in certain cases, advance receipt vouchers also require IRN generation. Many businesses activating e-invoicing overlook this and continue to issue credit notes manually — creating mismatch errors in the recipient's ITC reversal calculations.

E-invoicing in FY 2026-27

CBIC has further reduced the e-invoicing threshold since April 2023, moving consistently toward universal B2B coverage above a notified minimum. Verify the current applicable threshold directly on the GST portal (gst.gov.in → e-Invoice → Threshold Notification) before assuming the ₹5 crore figure still applies to your business in FY 2026-27. If your business recently crossed any new threshold during a preceding year, the obligation activates from 1 April of the following year — not mid-year.

HSN Code Reporting: Six-Digit Precision from 1 April 2023

Notification No. 78/2020 – Central Tax, as amended, established tiered HSN reporting in GST returns and invoices. From 01.04.2023, the effective requirements were:

This requirement applies simultaneously in three places: the tax invoice itself (HSN/SAC column), GSTR-1 Table 12 (HSN-level summary of outward supplies) and the e-invoice JSON schema (a mandatory field that the IRP validates at the time of IRN generation).

Why HSN accuracy matters more in 2026 than it did in 2023

GSTN now runs automated cross-validation between the HSN codes reported in GSTR-1, the e-invoice JSON and the e-way bill where a consignment is involved. A mismatch — for example, reporting HSN 8471 (computers, programmable) in GSTR-1 while the e-invoice JSON carries 8473 (parts and accessories for computers) — triggers a DRC-01C notice to the supplier. More damagingly, it can cause the recipient's ITC from that invoice to appear as mismatched in GSTR-2B, shifting the compliance burden and ITC denial risk downstream to your buyer.

The risk is asymmetric: your HSN coding error becomes your customer's ITC problem.

How to validate and correct your HSN master before the next return cycle

1. Export your billing software's complete HSN master list to a spreadsheet
2. Cross-check each code against the CBIC HSN search utility (cbic-gst.gov.in → Customs → HSN Finder) — this is the authoritative source, not the codes loaded during ERP implementation in 2017 or 2018
3. Ensure all codes are at minimum 6 digits for turnover above ₹5 crore (8-digit preferred for precision and e-way bill compatibility)
4. Update the master in your billing software before raising the next invoice
5. For already-filed returns with incorrect HSN, use GSTR-1A (the amendment return for the current month) to correct HSN data before GSTR-3B is filed for that period
6. Cross-check Table 12 of your next GSTR-1 to confirm the corrected codes are flowing through correctly

Sequential Filing of GSTR-1 and GSTR-3B: How the Portal Enforces It

GSTN tightened sequential filing enforcement in phases, with the 2022-23 notification cycle cementing the current rules. As at FY 2026-27, the portal enforces:

• GSTR-1 filing is blocked if your GSTR-3B for the previous tax period has not been filed
• For taxpayers with two or more consecutive pending GSTR-3B returns, both GSTR-1 and GSTR-3B filing access is locked until returns are filed in strict chronological order

For a monthly filer, this means: you cannot file April 2025 GSTR-1 (due 11 May 2025) until March 2025 GSTR-3B is filed. If you are two months behind on GSTR-3B, even filing GSTR-1 for the oldest period is blocked until the GSTR-3B sequence is cleared first.

The late fee compounding problem — with numbers

Late fees for GSTR-3B accrue under Section 47 at ₹50 per day (₹25 CGST + ₹25 SGST) for returns with tax liability, and ₹20 per day (₹10 + ₹10) for nil returns, subject to a maximum of ₹10,000 per return per Act.

Late fees for GSTR-1 accrue at ₹50 per day for non-nil returns, with a maximum of ₹10,000 per return per Act (currently further capped by CBIC notification for small taxpayers — verify the current cap).

A single taxpayer operating in three states who lets GSTR-3B and GSTR-1 fall 90 days behind on a non-nil return accumulates:

• GSTR-3B late fee: ₹50 × 90 days = ₹4,500 per GSTIN × 3 GSTINs = ₹13,500
• GSTR-1 late fee: ₹50 × 90 days = ₹4,500 per GSTIN × 3 GSTINs = ₹13,500
• Total late fees: ₹27,000 — before any interest on unpaid tax liability under Section 50 (18% p.a.)

This does not include the downstream cost of buyers unable to claim ITC during the blocked period, which often exceeds the late fee amount itself.

GST Amnesty Schemes for GSTR-4, GSTR-9 and GSTR-10 Non-Filers

Three separate amnesty notifications were issued on 31.03.2023, all effective 01.04.2023, to address the substantial backlog of non-filers accumulated since GST's inception in July 2017.

GSTR-4 Amnesty (Notification No. 02/2023 – Central Tax)

Who: Composition taxpayers registered under Section 10 of the CGST Act with pending GSTR-4 annual returns for FY 2017-18 to FY 2021-22.

Benefit: Late fee in excess of the notified cap was waived — ₹250 per return for nil-tax returns and ₹1,000 per return for returns with tax liability — provided the return was filed within the amnesty window (01.04.2023 to 30.06.2023, subsequently extended by CBIC).

If you are a composition dealer with outstanding GSTR-4 returns and all amnesty windows have now lapsed, the regular late fee under Section 47 applies in full. File the return immediately and verify whether CBIC has notified any subsequent amnesty extension before paying.

GSTR-9 Amnesty (Notification No. 07/2023 – Central Tax)

Who: All registered taxpayers (other than those covered under specific exemptions) with pending GSTR-9 annual returns for FY 2017-18 to FY 2021-22.

Benefit: Late fee was capped at ₹20,000 per return (₹10,000 CGST + ₹10,000 SGST), regardless of the actual accumulated amount.

The regular GSTR-9 late fee under Section 47 is ₹100 per day (₹50 CGST + ₹50 SGST), subject to a maximum of 0.25% of the taxpayer's turnover in the state for that year. For a taxpayer with ₹8 crore state turnover who had delayed GSTR-9 by 600 days, the pre-amnesty exposure was ₹60,000. Filing within the window capped liability at ₹20,000 — a saving of ₹40,000 per return.

GSTR-10 Amnesty (Notification No. 08/2023 – Central Tax)

Who: Taxpayers whose GST registration was cancelled but who had not filed the mandatory final return in Form GSTR-10 within the statutory three-month period from the cancellation date.

Benefit: Late fee was capped at ₹1,000 (₹500 CGST + ₹500 SGST). The standard late fee for GSTR-10 non-filing under Section 47 accumulates at ₹200 per day with no statutory maximum, making multi-year delays potentially very expensive.

Practical consequence of missing GSTR-10: the cancelled registration remains procedurally open, which means the electronic cash ledger balance cannot be released and refund claims are blocked. If your window has lapsed, file GSTR-10 now, calculate the applicable late fee using the GST portal's late fee module, and pay before filing — otherwise the return will be rejected.

Section 62 Deemed Withdrawal: The Exit Window Most Taxpayers Miss

Under Section 62 of the CGST Act 2017, when a registered person fails to file a return even after receiving a notice under Section 46 (return filing notice), the Proper Officer may assess the tax liability based on available information and pass a best-judgment assessment order.

Section 62(2) is the critical provision: if the taxpayer files the pending return within 30 days of service of the assessment order, the order is deemed withdrawn — provided the return shows a self-assessed liability equal to or greater than the assessed demand.

This means you do not need to file an appeal, engage a consultant to write an adjudication reply, or pay any additional demand. Filing the correct return within 30 days is the entire remedy.

How to act on a Section 62 order today:

1. Log into the GST portal → Services → User Services → View Notices and Orders
2. Note the date the order was served (the portal login timestamp, not the order's issue date)
3. File the pending return within 30 days of that service date — with correct self-assessed liability
4. The demand is automatically withdrawn; no separate intimation is required
5. If the 30-day window has closed, the demand survives; your options are an appeal under Section 107 (within three months of the order) or, if eligible, settlement under Section 128A for pre-2020 demand periods

Worked Example: MSME Caught by Multiple April 2023 Changes

Scenario: Aditya Metal Works Pvt. Ltd., Ahmedabad. Aggregate PAN-level turnover: ₹7.2 crore in FY 2022-23. Monthly GSTR-1 filer. GSTR-9 for FY 2021-22 was pending when the amnesty opened.

Problem 1 — E-invoicing not activated on 01.04.2023: Aditya Metal continued issuing invoices through their ERP without IRP integration through April and May 2023 — approximately 180 B2B invoices totalling ₹1.4 crore in value and ₹25 lakh in GST. None of these had IRNs.

Consequence: Three downstream buyers filed GSTR-3B claiming ITC based on these invoices, but none of the invoices appeared in the IRP database. GSTN's automated matching flagged the discrepancy, and buyers received DRC-01C notices asking them to either reverse the ITC or produce an explanation. Aditya Metal faced a penalty exposure under Section 122(1)(ii) for issuing invoices in contravention of Rule 48(4).

Fix for past periods: IRNs cannot be generated retrospectively. Aditya Metal issued credit notes for the affected invoices (requiring IRN since they are above threshold) and re-issued fresh e-invoices through IRP. This reset the ITC clock for buyers but created cash flow timing issues spanning two GST periods.

Problem 2 — HSN codes at 4-digit instead of 6-digit: All invoices used HSN 7308 (structures of iron or steel) at 4 digits. The correct 6-digit code was 730890 (other structures). GSTR-1 Table 12 filed with 4-digit codes triggered automated mismatch flags.

Fix: GSTR-1A amendment return was used to correct HSN for the two affected periods. The HSN master in the ERP was updated before the June 2023 GSTR-1.

Problem 3 — GSTR-9 for FY 2021-22 pending: Pre-amnesty accumulation: 390 days at ₹100/day = ₹39,000 late fee. Filing within the amnesty window (before 30 June 2023) capped liability at ₹20,000. Saving: ₹19,000 for one return.

Total cost of non-compliance across these three issues in a single financial year: over ₹60,000 in late fees and penalties, plus three months of corrective work across legal, accounts and IT teams — for a ₹7 crore MSME that simply did not track the April 2023 notification calendar.

Common Mistakes and Pitfalls to Avoid

1. Assuming e-invoicing applies only to sales invoices. Credit notes, debit notes and advance receipt vouchers for services also require IRN generation when e-invoicing is mandatory. A credit note without IRN creates an unresolvable mismatch when the buyer reverses ITC in their IMS/GSTR-2B workflow.

2. Using HSN codes from 2017-era ERP masters. CBIC has aligned GST HSN with Customs Tariff changes multiple times since 2017. Codes that were valid at implementation may have been reallocated, split or deleted. Always validate against cbic-gst.gov.in — not your ERP's original master.

3. Treating sequential filing blocks as a portal technical error. When GSTR-1 filing is blocked because GSTR-3B is pending, this is deliberate system design. No amount of helpdesk calls resolves it. File the blocking GSTR-3B (even late, even with late fees) before attempting GSTR-1.

4. Missing the 30-day window under Section 62(2). Taxpayers who receive a Section 62 order often wait for a recovery notice or legal demand before responding. By then, the automatic withdrawal window has closed. Read Section 62 orders the same week they appear in the portal inbox.

5. Not reviewing IMS before filing GSTR-3B in FY 2026-27. Since October 2024, invoices you have rejected or left pending in the Invoice Management System directly affect the ITC available in GSTR-3B. Filing GSTR-3B without a prior IMS review in each period locks incorrect ITC figures into the return.

6. Applying e-invoicing threshold to individual GSTINs rather than PAN-level aggregate. This is the most common error in multi-state businesses. A single GSTIN below ₹5 crore is not the right test. Aggregate all GSTINs under the PAN — including dormant or low-activity GSTINs — before concluding you are below threshold.

How These Rules Have Deepened in FY 2026-27

The April 2023 notifications were foundational. The compliance architecture in FY 2026-27 builds directly on them:

Invoice Management System (IMS): Launched October 2024, IMS allows every GST-registered recipient to accept, reject or mark as pending each B2B invoice in their GSTR-2B before filing GSTR-3B. Accepted invoices flow as eligible ITC. Rejected invoices auto-notify the supplier. Train your accounts payable team to complete IMS actions before the 20th of each month — unreviewed invoices are treated as "pending" and do not automatically flow into ITC.

GSTR-1A — the amendment return: Allows suppliers to correct GSTR-1 data (including HSN codes, invoice amounts and recipient details) after the GSTR-1 is filed but before GSTR-3B for the same period is submitted. This closed the long-standing loop where errors locked into GSTR-1 had no fix until the annual GSTR-9.

Section 128A settlement (Finance Act 2024): Interest and penalty on Section 73 demands (non-fraud cases) for FY 2017-18 to FY 2019-20 can be waived if the tax principal is paid by the notified cut-off. This is the successor-generation amnesty to the April 2023 schemes — and businesses that cleaned up their GSTR-9 backlogs in 2023 are now better placed to use Section 128A because their liability positions are documented and reconciled.

Biometric Aadhaar authentication for new registrations: Rolling out across identified high-risk states, requiring applicants to visit a GST Suvidha Kendra for biometric verification. Plan 10–15 additional working days for new registration timelines in affected states.

E-way bill and e-invoice cross-validation: GSTN now matches IRNs from GSTR-1 against e-way bill data at the individual invoice level. A supplier who generates an e-way bill without a corresponding e-invoice (or files GSTR-1 with an IRN that does not match the e-way bill document number) receives a system-generated discrepancy flag before the next return is due. Build a monthly three-way reconciliation between your IRN register, e-way bill register and GSTR-1 filed data.

Key Takeaways

• E-invoicing threshold dropped to ₹5 crore from 01.04.2023 under Notification No. 10/2023 – Central Tax. The threshold has been reduced further since. Verify the current notified threshold before each new financial year begins and confirm compliance obligations for every GSTIN under your PAN.
• Six-digit HSN codes are mandatory in B2B invoices, e-invoice JSON payloads and GSTR-1 Table 12 for taxpayers above ₹5 crore aggregate turnover. GSTN's automated mismatch detection means HSN errors generate DRC-01C notices and can deny your customers' ITC.
• Sequential filing is portal-enforced, not advisory. A pending GSTR-3B blocks GSTR-1 filing. A 90-day lag on a non-nil return across three state GSTINs costs ₹27,000 in late fees before any interest calculation begins.
• Three amnesty windows opened on 01.04.2023 — for GSTR-4 (Notification No. 02/2023), GSTR-9 (Notification No. 07/2023) and GSTR-10 (Notification No. 08/2023). If those original windows have lapsed and you still have pending returns, file immediately at full late fee and check for any subsequent CBIC extension notification.
• Section 62(2) gives you exactly 30 days from service of a best-judgment assessment order to file the pending return and have the order automatically withdrawn. Miss this window and a simple late-filing problem becomes a formal demand requiring appeal or litigation.
• In FY 2026-27, IMS review before GSTR-3B and GSTR-1A amendments after GSTR-1 are the two new mandatory steps in the monthly compliance calendar. Neither is optional if you want clean ITC records and no downstream DRC notices.
• The tri-reconciliation test — matching IRN data from IRP, e-way bill data from the NIC portal and your GSTR-1 filings at individual invoice level — is now the baseline hygiene check for any business with meaningful B2B turnover. Run it monthly, not annually.