Every GST-registered business files returns, but you do not need to understand the whole GST law to stay compliant. For most small businesses, monthly compliance is really about two forms: GSTR-1 and GSTR-3B. Get these two right and you are 90% of the way there.
The one-line version: GSTR-1 tells the government what you sold. GSTR-3B is where you summarise everything and pay the tax.
GSTR-1: your sales return
GSTR-1 is a statement of all your outward supplies — every sale you made in the period. This is important because the details you report here flow into your buyers' records and let them claim input tax credit. If you under-report, your customers suffer; if you over-report, you pay too much.
It includes B2B invoices, B2C sales, exports, and any credit or debit notes you issued.
GSTR-3B: your summary and payment return
GSTR-3B is a summary return. You declare your total sales, the GST collected, the input tax credit you are claiming on purchases, and then pay the net tax. This is the return where money actually changes hands.
Before filing it, check GSTR-2B — an auto-generated statement of the input tax credit available to you based on what your suppliers filed. Claim only what appears there, or you risk a mismatch notice.
Due dates you need to remember
| Return | Monthly filer | Quarterly (QRMP) |
|---|---|---|
| GSTR-1 | 11th of next month | 13th of month after quarter |
| GSTR-3B | 20th of next month | 22nd or 24th after quarter (state-wise) |
Dates can shift when the government issues extensions, so it is worth confirming on the GST portal each period.
The QRMP scheme: a break for small businesses
If your turnover is up to ₹5 crore, the QRMP scheme (Quarterly Return, Monthly Payment) lets you file GSTR-1 and GSTR-3B once a quarter instead of every month. You still pay tax monthly through a simple challan (PMT-06), but you only do the full filing four times a year. For a busy shop, this is a big reduction in paperwork.
Late fees and interest
Missing a due date costs money in two ways:
- Late fee — a per-day charge for each return filed late (a lower rate applies to nil returns), subject to caps.
- Interest — charged at 18% per year on any tax you pay late.
Neither is huge on its own, but they add up and they attract attention. The easiest fix is to keep your sales data clean all month so filing is a five-minute job, not a scramble.
The real secret to easy returns: it is not the filing — it is the record-keeping. If every bill is captured correctly as you go, your GSTR-1 is basically already done. That is where a good billing app pays for itself.
Make return season a five-minute job
DAM keeps every sale GST-ready so your GSTR-1 data is done before you file — free Gold plan until 31 March 2027.
Download DAM FreeFrequently asked questions
What is the difference between GSTR-1 and GSTR-3B?
GSTR-1 is a detailed statement of your sales (outward supplies). GSTR-3B is a summary return where you declare totals, claim input tax credit and pay the net GST.
Can I file GST returns quarterly?
Yes. Under the QRMP scheme, businesses with turnover up to ₹5 crore can file GSTR-1 and GSTR-3B quarterly while paying tax monthly through a challan.
What happens if I file GST returns late?
A per-day late fee applies (lower for nil returns) plus interest at 18% per year on any tax paid late. Repeated delays can also block your e-way bill generation.