GST Compliance Calendar for Small Businesses in India

GST compliance is easier when businesses treat it as a recurring process rather than a last-minute return-filing task.

A practical compliance calendar helps small businesses know what needs attention every day, every month, every quarter and at the end of the financial year. It can cover GST invoices, sales records, purchases, input tax credit, GSTR-1, GSTR-3B, e-invoices, e-way bills, tax payments and annual reconciliations.

For retailers, wholesalers, distributors, service providers and other MSMEs, following a GST compliance calendar can reduce missed deadlines and make month-end reconciliation more manageable.

This guide explains the key GST compliance activities small businesses in India should track throughout the year.

What Is a GST Compliance Calendar?

A GST compliance calendar is a schedule of recurring GST-related activities, filing dates and internal review tasks.

It helps a business answer questions such as:

• When should sales invoices be reviewed?
• When is GSTR-1 generally due?
• When should GSTR-2B be checked?
• When should ITC reconciliation happen?
• When is GSTR-3B generally filed?
• What changes for QRMP taxpayers?
• When should composition taxpayers file CMP-08?
• Which activities need to happen throughout the year rather than on one filing date?

A compliance calendar is most useful when it tracks both statutory deadlines and internal preparation dates.

For a more detailed task-by-task review, businesses can also use our GST compliance checklist for small businesses alongside this calendar.

GST Compliance Calendar at a Glance

Not every obligation applies to every taxpayer, but the following is a useful working schedule.

Exact due dates can be extended through government notifications, so businesses should always verify the GST Portal before filing.

Monthly GST Compliance Calendar for Regular Taxpayers

Most regular taxpayers need a recurring monthly process involving sales, purchases, ITC and return filing.

Here is a practical month-end cycle.

Day 1–5: Close the Previous Month's Books

The first few days of the month should be used to close the previous month's transaction records.

Review:

• Sales invoices
• Purchase invoices
• Credit notes
• Debit notes
• Cancelled invoices
• Advance receipts, where relevant
• Export/SEZ transactions, where applicable
• Reverse-charge transactions
• Stock and purchase entries
• Payment records

The objective is to make sure all transactions relating to the previous tax period are captured before return preparation begins.

Businesses should also review whether invoices contain the correct GSTIN, invoice number, HSN/SAC, GST rate and place of supply.

For a detailed invoice-level review, use the GST invoice mandatory fields checklist before finalising return data.

Day 5–10: Reconcile Sales and Prepare GSTR-1

After the books have been updated, compare the sales register with the outward-supply details that will be reported in GSTR-1.

Check:

• B2B invoices
• B2C transactions
• Credit notes
• Debit notes
• Export invoices
• Amendments
• Cancelled documents
• E-invoice records
• Taxable values
• GST amounts

For monthly filers, Form GSTR-1 is generally due by the 11th day of the succeeding month, unless the government extends the due date. Quarterly filers generally file GSTR-1 by the 13th of the month following the quarter.

Suggested internal deadline

Don't plan to complete sales reconciliation on the statutory due date itself.

A better internal target is:

Books closed → sales reconciliation completed → GSTR-1 reviewed → file before due date

This creates time to investigate invoice mismatches.

Around the 11th–14th: Review Supplier Data and GSTR-2B

After suppliers file their outward-supply data, businesses should review purchase-side information.

The GST Portal states that GSTR-2B for monthly recipients is generally generated on the 14th day of the succeeding month. For quarterly recipients, it is generated on the 14th day of the month following the quarter.

Compare GSTR-2B with your purchase register.

Look for:

• Missing supplier invoices
• Duplicate invoices
• Incorrect GSTINs
• Credit notes
• Debit notes
• Tax-value mismatches
• Invoices belonging to another period
• ITC requiring eligibility review

The GST Invoice Management System can also form part of this review process. For more detail on how supplier records can be accepted, rejected or kept pending, read the GST Invoice Management System guide for MSMEs.

Day 14–18: Reconcile Input Tax Credit

Once GSTR-2B is available, complete the ITC reconciliation before preparing GSTR-3B.

Compare:

Purchase register → supplier invoices → GST IMS → GSTR-2B → accounting records

Review:

• ITC appearing in books and GSTR-2B
• Invoices in books but missing from GSTR-2B
• Documents in GSTR-2B but missing from books
• Duplicate credit
• Restricted or ineligible ITC
• Credit notes
• Debit notes
• Reverse-charge transactions
• Import-related ITC where applicable

Do not assume that an invoice appearing in GSTR-2B automatically means ITC can be claimed. Applicable GST eligibility conditions still need to be satisfied.

Your internal calendar should therefore reserve a few days specifically for purchase and ITC reconciliation, rather than performing this review immediately before filing GSTR-3B.

Around the 20th: GSTR-3B for Monthly Filers

For many regular monthly filers, GSTR-3B is generally due on the 20th of the succeeding month, subject to the taxpayer's applicable filing arrangement and any notified extension. GST Portal guidance identifies GSTR-3B as the summary return through which liability, ITC and tax-payment information is reported.

Before filing, review:

• Outward taxable supplies
• Exempt/nil-rated supplies where relevant
• Reverse-charge liability
• Eligible ITC
• ITC reversals
• Tax payable
• Cash ledger
• Credit ledger
• Interest or other liabilities where applicable

The final check should compare:

Books → GSTR-1 → GSTR-2B → GSTR-3B

If there are material differences, investigate them rather than filing solely from auto-populated values.

Monthly GST Calendar for QRMP Taxpayers

Eligible businesses using the Quarterly Return Monthly Payment (QRMP) scheme have a different compliance cycle.

Instead of filing GSTR-1 and GSTR-3B every month, qualifying taxpayers generally file these returns quarterly while making tax payments for the first two months of the quarter.

Month 1 of the Quarter

Example: April, July, October or January.

Key activities:

• Maintain sales and purchase records
• Reconcile invoices
• Review ITC
• Pay applicable tax using PMT-06
• Use IFF if required for eligible B2B invoices

For the first two months of a QRMP quarter, the GST Portal states that tax payment through Form GST PMT-06 is generally due by the 25th of the succeeding month.

Month 2 of the Quarter

Repeat the same process.

Key activities:

• Update records
• Review supplier invoices
• Reconcile ITC
• Pay applicable tax
• Use IFF where appropriate

IFF is optional. It allows quarterly filers to furnish eligible B2B invoice information during the first two months of a quarter.

The GST Portal states that IFF generally expires after the 13th of the following month for the relevant first or second month of the quarter.

Month 3 of the Quarter

The third month is the quarter-end compliance month.

Review:

• Full quarter sales
• Purchases
• Credit/debit notes
• ITC
• Previous monthly payments
• GSTR-1
• GSTR-3B

Quarterly GSTR-1 is generally due on the 13th of the month following the quarter.

Quarterly GSTR-3B is generally due on the 22nd or 24th of the month following the quarter, depending on the taxpayer's principal place of business.

Because these dates vary by location, QRMP businesses should verify their specific due date on the GST Portal.

GST Compliance Calendar for Composition Taxpayers

Composition taxpayers have a different return and payment structure from regular GST taxpayers.

The two key compliance checkpoints are generally:

CMP-08

CMP-08 is the quarterly statement for payment of self-assessed tax by composition taxpayers.

The standard due date is generally the 18th of the month following the quarter, subject to extensions.

GSTR-4

Composition taxpayers generally file annual GSTR-4.

GST Portal guidance lists the standard due date as 30 April following the relevant financial year, unless extended.

A composition taxpayer should therefore maintain records throughout the year rather than waiting until CMP-08 or GSTR-4 filing dates.

Quarterly GST Compliance Calendar

Even businesses filing monthly returns should perform a deeper quarterly review.

At the end of:

• June
• September
• December
• March

review the following areas.

1. Sales Reconciliation

Compare:

• Sales register
• GSTR-1
• E-invoice data
• Credit/debit notes
• Customer ledgers

Investigate unresolved differences.

2. Purchase and ITC Reconciliation

Review:

• Purchase register
• GSTR-2B
• IMS actions
• Missing supplier documents
• Ineligible ITC
• ITC reversals
• Supplier corrections still pending

Quarterly reviews are particularly useful for identifying suppliers whose invoices repeatedly fail to appear correctly.

3. GST Invoice Quality Review

Take a sample of invoices and verify:

• GSTIN
• Invoice numbering
• Invoice date
• HSN/SAC
• GST rate
• Tax calculation
• Place of supply
• CGST/SGST versus IGST
• Reverse-charge status
• IRN/QR code where applicable

For a complete monthly and quarterly review framework, see the GST Compliance Checklist for MSMEs in FY 2026-27.

E-Invoice Compliance Calendar

For businesses covered by e-invoicing, IRN generation should not be treated as a month-end compliance task.

It belongs in the daily invoicing workflow.

For each applicable invoice:

Create invoice → validate data → report to IRP → obtain IRN → verify signed QR code → issue invoice

Businesses should regularly monitor:

• Invoices without IRNs
• Rejected submissions
• Duplicate IRNs
• Incorrect recipient GSTIN
• Incorrect place of supply
• Credit/debit notes
• Cancelled transactions

Important 30-day control

For taxpayers with AATO of ₹10 crore or more that fall within the current restriction, applicable e-invoice documents need to be reported to the IRP within 30 days of the document date.

Businesses subject to this rule should maintain an invoice-ageing control rather than waiting until GST return filing.

Use the e-invoice 30-day reporting checklist to track IRN generation, invoice ageing and exceptions.

E-Way Bill Compliance Calendar

E-way bill compliance is transaction-driven rather than tied to one monthly due date.

Where applicable, checks should happen before goods are dispatched.

Verify:

• Invoice or delivery challan
• Consignor
• Consignee
• GSTIN
• Dispatch location
• Delivery location
• Goods description
• HSN
• Value
• Transporter
• Vehicle number
• Distance
• E-way bill validity

Businesses with frequent goods movement should also review open e-way bills daily.

Instead of checking e-way bills only at month-end, maintain a status report showing:

• Active
• Near expiry
• Cancelled
• Expired
• Delivered/completed
• Exception cases

For the operational process, use our guide on tracking active, cancelled, expired and closed e-way bills.

Year-End GST Compliance Calendar

March should not be the first time the business reviews annual GST records.

A year-end review should begin before the financial year closes.

February–March: Pre-Year-End Review

Check:

• Missing sales invoices
• Missing purchase invoices
• Unresolved vendor discrepancies
• ITC differences
• Credit notes
• Debit notes
• Advances
• Reverse-charge transactions
• E-invoice mismatches
• E-way bill exceptions
• Turnover
• GST registrations
• Branch transactions

This gives the accounts team time to resolve problems while relevant transaction information is still easily available.

March 31: Financial Year Closing

At year-end, businesses should ensure their GST-related records align with their accounting books.

Review:

Sales register → purchase register → GST returns → ledgers → e-invoice data → e-way bills

Identify differences before finalising annual accounts.

April: Start the New Financial Year Correctly

April is more than another GST filing month.

Businesses should also review operational settings for the new financial year.

Check:

• Invoice number series
• Customer masters
• Supplier masters
• GSTINs
• Product/service masters
• HSN/SAC
• GST rates
• Branch configurations
• Tax settings
• Billing templates

Invoice numbering is particularly important because GST invoices need unique serial numbers within the financial year.

Annual GST Return Review

Businesses required to file the applicable annual GST return should start reconciliation before the final due date.

Annual review may include:

• GSTR-1 totals
• GSTR-3B totals
• Books of accounts
• Sales register
• Purchase register
• ITC
• Tax payments
• Credit/debit notes
• Turnover
• Reverse-charge transactions
• E-invoice data
• Other applicable adjustments

For taxpayers required to furnish GSTR-9C, GST Portal guidance states that the standard due date is 31 December of the subsequent financial year, unless extended by notification.

Because annual-return applicability can depend on the taxpayer and prevailing rules, businesses should confirm current requirements before filing.

GST Compliance Calendar by Business Type

Different businesses should emphasise different tasks.

Conditional GST Compliance Dates Small Businesses Should Track

Some compliance requirements apply only to specific taxpayers.

Your calendar may also need to track:

• GST TDS
• GST TCS
• LUT
• Exports
• SEZ transactions
• E-invoicing
• E-way bills
• Reverse charge
• Composition scheme
• QRMP
• Annual return
• Reconciliation statement

For example, businesses or entities required to deduct GST TDS may need to file GSTR-7. GimBooks has a dedicated guide explaining how to file GSTR-7 and comply with TDS under GST.

Do not add a compliance deadline to your calendar simply because another business follows it. First confirm whether the requirement applies to your GST registration and transaction type.

Monthly GST Compliance Checklist to Add to Your Calendar

Use this quick checklist at the end of every month.

Sales

• ☐ All sales invoices recorded
• ☐ Credit/debit notes recorded
• ☐ Cancelled invoices reviewed
• ☐ Sales register reconciled
• ☐ GSTR-1 data reviewed

Purchases

• ☐ All purchase invoices recorded
• ☐ Supplier GSTINs checked
• ☐ Missing invoices followed up
• ☐ Purchase register reconciled

ITC

• ☐ GSTR-2B downloaded/reviewed
• ☐ GST IMS checked where relevant
• ☐ Eligible ITC reviewed
• ☐ Ineligible/restricted ITC identified
• ☐ Reversals/reclaims reviewed

Returns

• ☐ GSTR-1 filed where applicable
• ☐ GSTR-3B reviewed
• ☐ Applicable tax paid
• ☐ Filed return acknowledgement retained

E-Invoice

• ☐ All applicable documents have IRNs
• ☐ Rejected invoices resolved
• ☐ 30-day ageing monitored where applicable

E-Way Bill

• ☐ Active e-way bills reviewed
• ☐ Expired/cancelled bills reconciled
• ☐ Delivered movements matched with invoices

Books and Records

• ☐ Cash/bank records updated
• ☐ Customer ledgers reviewed
• ☐ Supplier ledgers reviewed
• ☐ GST records backed up
• ☐ Open discrepancies documented

Sample Monthly GST Compliance Calendar

A small business can use the following internal schedule.

This is a working internal calendar, not a substitute for checking the GST Portal for the applicable period.

Common GST Compliance Calendar Mistakes

Waiting Until the Due Date

If return preparation begins on the filing date, there is little time to resolve supplier or invoice errors.

Better approach: Create internal deadlines several days before statutory deadlines.

Reviewing ITC Only Once a Quarter

Businesses with monthly reporting should monitor purchase and ITC data regularly.

Better approach: Make GSTR-2B and supplier reconciliation a recurring month-end task.

Treating E-Invoices as Month-End Work

E-invoice requirements operate at document level.

Better approach: Generate and validate IRNs as part of invoicing.

Ignoring E-Way Bill Expiry

Goods may still be in transit even when finance teams assume the transaction is complete.

Better approach: Track active and near-expiry e-way bills daily.

Using One Calendar for Every GSTIN

Multi-state or multi-GSTIN businesses may have different teams, documents and return responsibilities.

Better approach: Maintain a GSTIN-wise compliance tracker.

Forgetting Extensions and Notifications

GST deadlines can be extended for specific periods or taxpayers.

Better approach: Treat the calendar as a control framework and verify actual filing dates through official GST communications.

How GST Billing Software Can Help Manage Your Compliance Calendar

A compliance calendar works best when the underlying transaction data is organised throughout the month.

If invoices, purchase records, e-invoices, e-way bills and payment information are maintained separately, the accounts team has to consolidate everything before filing.

GST billing software such as GimBooks can help businesses manage:

• GST invoices
• Customer and supplier records
• Product and service masters
• HSN/SAC
• GST calculations
• Purchases
• Inventory
• E-invoices
• E-way bills
• Credit and debit notes
• Payments
• Reports

This reduces the amount of transaction data that needs to be recreated during GST reconciliation.

The goal is not simply to remember a filing date. It is to have the records ready before the deadline arrives.

Frequently Asked Questions

What is a compliance calendar under GST?

A GST compliance calendar is a schedule used to track recurring GST tasks such as invoicing, sales reconciliation, purchase reconciliation, GSTR-1, GSTR-2B review, GSTR-3B, tax payments and other applicable GST obligations.

What are the monthly GST compliance dates?

For many regular taxpayers, monthly GSTR-1 is generally due on the 11th of the following month, GSTR-2B becomes available around the 14th and monthly GSTR-3B is generally due around the 20th. Actual dates depend on the taxpayer and can be extended, so they should be verified on the GST Portal.

What is the GST calendar for QRMP taxpayers?

QRMP taxpayers generally pay tax for the first two months of a quarter using PMT-06 and file GSTR-1 and GSTR-3B quarterly. IFF can optionally be used for eligible B2B invoices in the first two months.

When is GSTR-1 generally due?

For monthly filers, GSTR-1 is generally due on the 11th of the succeeding month. For quarterly filers, it is generally due on the 13th of the month following the quarter, subject to extensions.

When should GSTR-2B be reviewed?

Monthly recipients generally receive GSTR-2B on the 14th of the following month. Businesses should review it before finalising ITC and GSTR-3B.

Is GST compliance only about filing returns?

No. GST compliance also involves correct invoicing, GSTIN verification, HSN/SAC, place of supply, ITC reconciliation, e-invoicing, e-way bills, tax payments and record maintenance.

Do small businesses need a GST compliance calendar?

A compliance calendar is useful for any GST-registered business with recurring filing or reconciliation requirements. It helps owners and accounts teams organise tasks before statutory deadlines.

Can GST billing software help manage compliance?

Yes. Billing software can help organise GST invoices, purchase records, tax calculations, e-invoices, e-way bills, payments and reports, making month-end compliance preparation easier.

Final GST Compliance Calendar for Small Businesses

A good compliance calendar should not simply list filing dates.

It should create a repeatable workflow:

Record transactions → review invoices → reconcile sales → file GSTR-1 → review GSTR-2B → reconcile ITC → prepare GSTR-3B → pay tax → resolve exceptions → retain records

For QRMP and composition taxpayers, the filing schedule changes, but the same principle applies: update and review GST records throughout the period instead of waiting until the return deadline.

Small businesses that maintain invoices, purchases, e-invoices, e-way bills and tax records consistently are better positioned to complete GST filing without a last-minute scramble.

GimBooks can help organise many of these billing and GST-related activities in one workflow, while the business remains responsible for checking which GST requirements and deadlines apply to its registration.