GST Compliance Calendar in India: Complete Annual Checklist for Small Businesses

Once you are registered under GST, the real work begins – staying compliant every month and every quarter. Late filings don’t just attract late fees and interest; they also block your customers’ input tax credit and can hurt your relationships. The good news is that with a clear calendar and a simple internal process, compliance can be predictable instead of stressful.

In this guide, I’ll walk you through a practical GST compliance calendar for small businesses, explain how late fees and interest work with simple examples, and share a checklist you can adapt to your own operations.

Core GST Returns for Small Businesses

The main periodic returns most small taxpayers deal with are:

• GSTR‑1: Statement of outward supplies (your sales/invoices)
• GSTR‑3B: Summary return with tax payment (a self-declaration of outward and inward supplies)
• GSTR‑9 / 9C: Annual return and, where applicable, reconciliation statement (for certain taxpayers)

Your frequency (monthly vs quarterly) depends on:

• Your turnover
• Whether you are under the QRMP scheme (Quarterly Return, Monthly Payment)

Monthly vs QRMP: How It Affects Your Calendar

Monthly Filers

Typically:

• File GSTR‑1 every month by the due date
• File GSTR‑3B every month by its due date

Monthly filing is common for:

• Higher turnover taxpayers
• Businesses that want more frequent ITC passing to customers

QRMP Scheme (Quarterly Return Monthly Payment)

Under QRMP:

• GSTR‑1 is filed quarterly
• GSTR‑3B is also filed quarterly
• Tax is paid monthly using challan or fixed sum method

This reduces the number of detailed returns but still requires monthly attention for cash flow.

Month-by-Month Compliance View (Illustrative)

While exact due dates can shift slightly (and differ by state / type of filer), a typical pattern for monthly filers is:

• By 11th of next month: GSTR‑1 for previous month
• By 20th of next month: GSTR‑3B for previous month

For QRMP filers, GSTR‑1 and GSTR‑3B deadlines are quarterly, while monthly tax payments fall:

• By 25th of the month following each month in the quarter (subject to scheme rules)

Because dates can change via notifications, the best approach is to:

• Maintain your own internal calendar
• Cross-check official notifications periodically or via your consultant

Late Fees and Interest: Why Missing Dates Hurts

If you file returns late:

• Late fee is charged per day of delay (subject to caps and frequent amnesty schemes)
• Interest is charged on net tax payable in cash for the delayed period

Example (simplified, illustrative):

• Net GST payable in cash for the month: ₹1,00,000
• Due date: 20th of the month
• You file and pay on 30th (10 days late)

Interest roughly:

• ₹1,00,000 × 18% per annum × (10/365) ≈ ₹493

Late fee is separate and depends on return type and state/central components; when repeated across months, this becomes significant.

Practical Monthly Checklist for GST

Here’s a simple checklist you can adapt:

Every Week:

• [ ] Record all sales invoices properly with correct GSTINs and tax splits
• [ ] Record purchase invoices and expense bills, tagging eligible ITC
• [ ] Validate new vendor GSTINs on the portal before first payment

Between 1st–10th of Each Month:

• [ ] Reconcile sales invoices for previous month
• [ ] Prepare and verify data for GSTR‑1
• [ ] Ensure no major duplications or missing invoices

Between 11th–20th of Each Month:

• [ ] Download GSTR‑2B for previous period
• [ ] Reconcile ITC with purchase register (at least for large vendors)
• [ ] Use our GST Calculator and GST Input Credit Calculator to verify tax liability and ITC
• [ ] Prepare and file GSTR‑3B and pay tax

Quarterly (QRMP) Specific:

• [ ] For QRMP, still check monthly cash liability and ITC movement
• [ ] Ensure quarterly GSTR‑1 and 3B align with cumulative monthly activity

Annual Compliance: GSTR‑9 and 9C

Depending on your turnover and current law:

• You may need to file GSTR‑9 (annual return) and in some cases GSTR‑9C (reconciliation statement certified by a professional).
• These returns are due after the end of the financial year and require:
• Reconciliation of sales as per returns with books
• Reconciliation of ITC claimed vs books and 2B/2A
• Review of any mismatches and corrections

Planning ahead:

• Maintain good monthly reconciliation so year-end work is mostly aggregation, not investigation.
• Keep organized digital records of invoices, returns, and payment challans.

Building a Simple Internal Compliance System

To make compliance sustainable:

• Designate a single owner internally (even if you use an external CA) responsible for reminders and data readiness
• Maintain a shared compliance calendar (Google Calendar/Notion/Excel) with:
• All GST due dates for the year
• Bank holidays and internal cut-offs a few days before official due dates
• Automate reminders (email/calendar notifications, practice management tools)

Final Thoughts

GST compliance is not just about avoiding penalties – it’s about smooth business operations, timely ITC for your customers, and maintaining credibility with vendors and authorities. A clear calendar and a simple checklist often make more difference than any complex software.

Take a couple of hours to map out your own GST calendar for the year, mark all key dates, and agree internal responsibilities. With that done, each month becomes a routine instead of a fire drill.

Disclaimer: Actual due dates, late fee caps, and annual return requirements change from time to time through CBIC notifications and circulars. This guide is for educational purposes based on current patterns. Always verify latest timelines on the official GST portal or with your GST professional before relying on specific dates.