What are the monthly GST compliance tasks?

Key monthly GST tasks include: filing GSTR-1 by 11th (monthly filers), filing GSTR-3B and paying tax by 20th, reconciling purchase register with GSTR-2B (available on 14th), verifying ITC eligibility, generating e-invoices for B2B transactions, and maintaining proper records of e-way bills issued and received.

What is the due date for GSTR-1 and GSTR-3B?

For monthly filers (turnover > ₹5 crore): GSTR-1 is due by the 11th, GSTR-3B by the 20th. For quarterly QRMP filers (turnover ≤ ₹5 crore): GSTR-1 is due by 13th of the quarter-end month, GSTR-3B by 22nd or 24th (state-dependent). Tax must be paid monthly via PMT-06 challan even for quarterly filers.

GST Compliance Checklist 2025-26 — Monthly Due Date Tracker

Pre-Filing (by 14th)

Download and review GSTR-2B for the month

GSTR-2B is auto-generated by 14th with ITC available from suppliers who filed GSTR-1

Reconcile GSTR-2B with purchase register

Match invoices — flag mismatches for vendor follow-up before filing GSTR-3B

Identify and reverse ineligible ITC (Section 17(5))

Block credit on motor vehicles, food, club memberships, etc.

Compute RCM liability for the month

GTA freight, legal services, import of services — calculate and prepare to pay in cash

Verify all sales invoices are correctly classified

B2B vs B2C, taxable vs exempt, intra-state vs inter-state

GSTR-1 Filing (by 11th)

File GSTR-1 for all B2B invoices (Table 4A)

Enter GSTIN, invoice number, date, value, GST rate for every B2B sale

Enter B2C consolidated summary (Table 7)

State-wise totals for B2C sales above ₹2.5 lakh; rest in B2C Others

File HSN-wise summary (Table 12)

Mandatory for turnover > ₹1.5 crore (4-digit); > ₹5 crore (6-digit)

Report exports (Table 6A/6B)

With payment of IGST or under LUT — include shipping bill details

Report credit/debit notes (Table 9)

All CDNs issued during the month to registered buyers

Verify GSTR-1 totals against sales register

Cross-check total value, taxable value, and GST amounts before submitting

GSTR-3B Filing & Payment (by 20th)

Compute output tax liability (Table 3.1)

Total CGST, SGST, IGST on all outward taxable supplies

Claim eligible ITC from GSTR-2B (Table 4)

Do NOT claim more than what appears in GSTR-2B

Enter RCM tax paid (Table 4D)

Include ITC of RCM paid in the same period if eligible

Pay net GST via PMT-06 challan

Cash payment via net banking or UPI — ITC set-off happens automatically

Pay late fee if filing after due date

₹50/day for GSTR-3B; ₹20/day for nil returns — cannot use ITC

File GSTR-3B and note ARN

Save Acknowledgement Reference Number as proof of filing

E-Invoice & E-way Bill (Ongoing)

Generate IRN for all B2B invoices (if turnover > ₹5 crore)

Must generate before or at time of invoice issuance — not retrospectively

Ensure QR code and IRN on all tax invoices

Print on physical invoice and PDF sent to buyer

Generate e-way bill for consignments > ₹50,000

Required before goods leave the premises — check distance-based validity

Update vehicle number in e-way bill if changed

Transporter must update Part B before goods resume movement

Cancel any incorrect IRNs within 24 hours

After 24 hours, cancellation is not allowed — generate fresh IRN instead

Records & Reconciliation (Monthly)

Maintain purchase register with GSTIN of all suppliers

Required for ITC eligibility — missing GSTINs = lost ITC

Reconcile output as per books with GSTR-1 filed

Differences must be explained and corrected in next period

Track ITC reversal obligations (Rule 42/43)

Proportionate reversal for common inputs used in exempt + taxable supplies

File GSTR-7 if deducting TDS under GST

By 10th of the following month — applicable to government entities and notified persons

Update accounting entries for all GST payments

Separate ledgers for CGST, SGST, IGST, and cash ledger balance