GST
GSTR-3B explained for small business owners
Your monthly GST summary and payment, in plain words — what it is, what goes in it, and how to avoid mismatches.
Key takeaways
- ▸ GSTR-3B is your monthly summary return and the one where you pay GST.
- ▸ It must tell the same story as GSTR-1 and GSTR-2B.
- ▸ It's usually due on the 20th (or 22nd/24th for QRMP, by state).
- ▸ Built from one set of books, it reconciles by design.
If GSTR-1 reports your sales in detail, GSTR-3B is the short monthly summary where you declare totals and actually pay your GST. Here's what goes into it without the jargon.
What GSTR-3B contains
- Total outward supplies (your sales) and the tax on them.
- Inward supplies liable to reverse charge.
- Input Tax Credit you're claiming for the period.
- The net tax payable — and you pay it when you file.
The number that matters: net tax
Your output tax (GST collected on sales) minus your eligible ITC (GST paid on purchases) is your net payable. Recording your purchase bills properly is what lets you reduce what you pay — skip them and you overpay.
Avoiding the mismatch trap
The most common GST notice comes from GSTR-3B not matching GSTR-1 (your sales) or your ITC not matching GSTR-2B (your purchases). When all three are built from one connected system, they line up automatically. When they live in different tools, you reconcile by hand and hope.
When it's due
Monthly filers: generally the 20th of the following month. Under QRMP, it's quarterly with monthly payment, due on the 22nd or 24th depending on your state. Late filing means interest and late fees, so a reminder helps.
The easy way
MGH Books prepares your 3B from the same invoices and bills you already recorded, flags mismatches against GSTR-1, and shows your net payable — you review and file on the portal.