10 Common GST Mistakes to Avoid in 2026

📅 Published: February 13, 2026 ⏱️ 8 min read
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Why This Matters

GST mistakes cost businesses lakhs in penalties and interest. Learn from others' errors and stay compliant!

1. Wrong HSN/SAC Codes

Mistake: Using incorrect HSN codes → Wrong tax rate, ITC rejected

Solution: Use HSN Finder to verify

2. Not Reconciling GSTR-2B

Mistake: Claiming ITC without checking GSTR-2B

Solution: Always reconcile before filing GSTR-3B

3. Missing 180-Day Payment Rule

Mistake: Not paying suppliers within 180 days

Solution: Pay within 150 days, track with reminders

4. Claiming Blocked ITC

Mistake: Claiming ITC on motor vehicles, food (Section 17(5))

Solution: Use ITC Calculator

5. Late Filing

Mistake: Filing returns late, even by 1 day

Solution: Set reminders 3 days before due date

6. Not Filing Nil Returns

Mistake: Skipping returns when no transactions

Solution: Always file nil returns - ₹500 penalty if skipped

7. Wrong Invoice Format

Mistake: Missing mandatory fields on invoices

Solution: Include GSTIN, invoice #, date, HSN, tax breakup

8. IGST vs CGST+SGST Confusion

Mistake: Wrong tax type for transaction

Solution: Inter-state = IGST, Intra-state = CGST+SGST

9. Poor Record-Keeping

Mistake: No digital backups, messy records

Solution: Keep all invoices 6 years, use accounting software

10. Ignoring Notices

Mistake: Not responding to GST portal notices

Solution: Check portal weekly, respond within deadline