GST Compliance Calendar for Small Businesses in Maharashtra

GST compliance is a continuous monthly calendar — not a year-end activity. For small businesses in Pune and across Maharashtra, missing even a single deadline cascades into interest charges, late fees, and Input Tax Credit blockage that can cost far more than the tax itself.

This guide covers every filing and payment obligation for regular GST taxpayers, updated to reflect the latest GSTN systems including IMS, GSTR-1A, and the current e-invoice threshold.

Step 1: Identify Your Return Category

Your filing obligations depend on your annual aggregate turnover (AAT):

| Turnover | Scheme | GSTR-1 | GSTR-3B | |---|---|---|---| | Up to ₹5 crore (opted in) | QRMP | Quarterly + IFF | Quarterly | | Up to ₹5 crore (not opted) | Regular | Monthly | Monthly | | Above ₹5 crore | Mandatory regular | Monthly | Monthly | | Composition dealers | Composition | Annual GSTR-4 | Quarterly CMP-08 |

QRMP (Quarterly Return, Monthly Payment): Taxpayers with turnover up to ₹5 crore can opt in. QRMP filers in Maharashtra (a Category I state) file GSTR-3B by the 22nd of the month following the quarter. Opting in or out is done on the GST portal by the last day of the preceding quarter.

Monthly Compliance Checklist

By 11th of Each Month

GSTR-1 — Report all outward supplies (invoices issued)

• Include all B2B invoices, B2C summary, debit/credit notes, and exports
• If you generate e-invoices, they auto-populate GSTR-1 — verify, do not re-enter manually
• QRMP filers: File IFF (Invoice Furnishing Facility) by 13th for B2B invoices only in months 1 and 2 of the quarter

By 14th of Each Month

GSTR-1A — Amendment window introduced from August 2024

• Allows correction of B2B invoice details already filed in GSTR-1 (wrong GSTIN, value, tax rate)
• Must be done before GSTR-3B is filed for that month
• Useful for genuine data entry errors — eliminates need to wait for the next GSTR-1 cycle

IMS (Invoice Management System) — Act on inward supply invoices

• From October 2024, recipients must Accept, Reject, or mark Pending each supplier invoice in IMS
• Accepted invoices flow into GSTR-2B and become eligible for ITC
• Inaction = deemed acceptance — but always verify to avoid claiming ITC on incorrect invoices
• Rejected invoices are communicated to suppliers for credit note issuance

By 14th of Each Month

GSTR-2B review — Auto-populated ITC statement

• Cross-check GSTR-2B against your purchase register / accounts payable ledger
• Identify suppliers who have not filed GSTR-1 — their invoices will not appear in your GSTR-2B
• You can only claim ITC on what appears in GSTR-2B (Rule 36(4) — no provisional ITC buffer)
• Follow up with non-compliant vendors; their lapse directly reduces your ITC

By 20th of Each Month

GSTR-3B — Summary return + tax payment

• Pay net tax liability (output tax minus eligible ITC)
• Interest at 18% per annum on net tax unpaid after the due date — calculated per day
• QRMP filers: file by 22nd (Maharashtra)

Quarterly Compliance (QRMP Taxpayers)

| Month in Quarter | Action | Due Date | |---|---|---| | Month 1 | File IFF for B2B invoices | 13th | | Month 1 | Pay tax via PMT-06 challan | 25th | | Month 2 | File IFF for B2B invoices | 13th | | Month 2 | Pay tax via PMT-06 challan | 25th | | Month 3 (quarter-end) | File full GSTR-1 | 13th | | Month 3 (quarter-end) | File GSTR-3B | 22nd (Maharashtra) |

PMT-06 payment options:

• Fixed Sum Method: Pay 35% of the tax paid in the last filed GSTR-3B
• Self-Assessment Method: Calculate actual liability for the month and pay exact amount

Annual Compliance

GSTR-9 — Annual Return

• Mandatory for taxpayers with turnover above ₹2 crore; optional below
• Due: 31 December of the next financial year
• Reconciles all outward supplies, ITC claimed, and tax paid across monthly returns for the full year
• Common adjustments include ITC reversals, credit/debit note reconciliation, and HSN summary

GSTR-9C — Self-Certified Reconciliation Statement

• Mandatory for taxpayers with turnover above ₹5 crore
• Filed together with GSTR-9
• Reconciles GSTR-9 data with audited financial statements (self-certified since FY 2020-21 — no separate CA certification needed, though many engage CAs for accuracy)

E-Invoice: Current Applicability

E-invoicing is mandatory for all registered taxpayers whose aggregate turnover exceeded ₹5 crore in any preceding financial year, for all B2B, B2G, and export transactions.

How it works:

1. Generate invoice in your accounting software / ERP
2. Upload JSON to any IRP (Invoice Registration Portal) — multiple IRPs are available
3. IRP validates and returns an IRN (Invoice Reference Number) and digitally signed QR code
4. Print IRN + QR code on the invoice before sharing with buyer
5. E-invoice auto-populates GSTR-1 and e-way bill Part A — no duplication needed

Important: An e-invoice not registered on IRP is treated as invalid for ITC purposes for the buyer.

Currently exempt from e-invoicing: SEZ units (outward), insurance/banking/NBFC companies, GTA, passenger transport, multiplex cinemas, and entities providing services only (verify latest CBIC notifications as applicability evolves).

ITC Compliance — Critical Rules

Rule 36(4): ITC is restricted to amounts appearing in GSTR-2B. There is no provisional ITC buffer — every rupee of ITC must be supported by a matching entry in GSTR-2B.

Blocked credits u/s 17(5) — never claimable regardless of business use:

• Motor vehicles (unless used for specific taxable supplies like transport, training, etc.)
• Food, beverages, outdoor catering
• Club memberships, health and fitness services
• Construction of immovable property (works contract)
• Personal consumption items

Rule 37A — ITC reversal: If a supplier does not file their GSTR-3B within 2 years from the invoice date, you must reverse the ITC claimed on that invoice. This is enforced through automated system-generated demands.

Penalty Reference

| Violation | Penalty | |---|---| | Late GSTR-1 | ₹50/day (₹20 for Nil return), max ₹10,000 | | Late GSTR-3B | ₹50/day (₹20 for Nil), max ₹10,000 + 18% p.a. interest on tax | | Late GSTR-9 | ₹200/day, max 0.25% of turnover | | Incorrect ITC claim | Recovery + up to 100% penalty | | E-invoice not generated | Invoice invalid; ITC blocked for buyer | | E-way bill violation | ₹10,000 or tax evaded, whichever is higher |

Practical Tips for Pune Businesses

1. Act on IMS by the 13th — Do not let inward invoices pile up. Accept promptly, reject errors early so suppliers can issue credit notes in time.
2. Compute tax liability by the 17th — Gives you 3 days buffer to verify and pay before the 20th.
3. Maintain a vendor compliance tracker — Vendors who consistently fail to file GSTR-1 should be replaced or paid only after verifying their filings. Their non-compliance directly erodes your ITC.
4. Track MSME payment status — Under Section 43B(h) of the Income Tax Act, payments to MSME suppliers outstanding beyond 45 days are disallowed as a deduction. Auditors now verify this in tax audit reports.
5. Reconcile GST turnover with books monthly — Differences between GSTR-1 turnover and books of accounts are a common notice trigger.

Need help setting up your monthly GST process? Contact us for a no-obligation discussion.

CA Mahesh M. Joshi (ACA) is a practising Chartered Accountant in Wakad, Pune. This article reflects GST rules and GSTN systems as currently applicable. Always verify current due dates on the GST portal — CBIC periodically extends deadlines via notifications.