Understand GSTR-1 and GSTR-3B returns for Indian GST filers. Learn what each covers, who must file, and key filing deadlines.
GSTR-1: Your Sales and Invoice Details
GSTR-1 is your outward supply return—it records every sale you've made in a month. Whether you sold goods, services, or both, this return captures:
- Invoice number, date, and amount
- Customer GSTIN (if B2B) or customer details
- HSN/SAC codes (product classifications)
- Tax rates applied and tax amounts
- Exempted or nil-rated supplies
Who files GSTR-1? Registered businesses with turnover exceeding ₹5 crore annually, or those with turnover ₹20 lakh–₹5 crore who opt for the regular scheme.
Filing deadline: By the 11th of the following month (e.g., January sales filed by February 11th). Businesses with turnover above ₹5 crore must file by the 10th.
GSTR-3B: Your Tax Liability Summary
GSTR-3B is a self-assessment return that summarizes your entire GST position for the month:
- Total outward supplies (sales with tax)
- Total inward supplies (purchases on which you paid GST)
- Input Tax Credit (ITC) claimed
- Net GST payable or refund due
- Tax payments already made
Think of GSTR-3B as your "bottom line"—what you owe the government after claiming credits.
Who files GSTR-3B? All registered businesses except those filing GSTR-1 (typically those below ₹20 lakh turnover).
Filing deadline: By the 20th of the following month (e.g., January tax due by February 20th).
Key Differences at a Glance
| Feature | GSTR-1 | GSTR-3B |
|---|---|---|
| What it shows | Invoice-level sales data | Monthly tax liability |
| Who files | High-turnover regular filers | Most GST-registered businesses |
| Filing deadline | 10th–11th of next month | 20th of next month |
| How detailed | Item-by-item invoice data | Summary with ITC calculation |
What If Your Turnover Is Below ₹20 Lakh?
If you're below the ₹40 lakh threshold (goods), ₹20 lakh (services), or ₹10 lakh (special states), you're likely unregistered and file nothing.
If you're voluntarily registered, file GSTR-3B only—no GSTR-1 needed.
Why Both Returns Matter
GSTR-1 ensures your customers can claim their input credit, so filing correctly prevents disputes. GSTR-3B determines what you actually owe, protecting you from overpayment or penalties.
Keep your invoices organized and reconcile sales records monthly. Use our free GST calculator at gsthelp.in to track your turnover, determine which return applies to you, and never miss a deadline.