Bigsun Udaan › Finance reference guides › GST lesson 5
TDS & Tax · GST lesson 5 of 5
Returns, due dates and final quiz
Registered businesses file returns to report sales and pay tax. Know the main ones, their dates and the cost of being late.
The main GST returns
| Return | What it reports | Usual due date |
|---|---|---|
| GSTR-1 | Sales (outward supplies) | 11th of the next month. Quarterly option (QRMP): 13th after the quarter |
| GSTR-2B | Auto-generated: purchase invoices and ITC available (you check it, you do not file it) | Generated every month |
| GSTR-3B | Summary of sales, ITC and tax payment | 20th of the next month. QRMP taxpayers: the 22nd or 24th of the month after the quarter, depending on the state |
| PMT-06 | Monthly tax payment for QRMP taxpayers | 25th of the next month |
| GSTR-9 | Annual return (with a reconciliation statement for larger businesses) | 31 December after the financial year |
The quarterly (QRMP) option is for taxpayers with turnover up to ₹5 crore. Dates can be extended by notification. Always check the GST portal calendar.
If you are late
- A late fee for GSTR-3B of about ₹50 a day (₹20 a day for nil returns), with a cap.
- Interest of 18% a year on tax paid late.
- For wrong or avoided tax, higher penalties can apply, and unpaid ITC claims can be reversed.
Other compliance you will hear about
- E-invoicing: businesses above a turnover limit (₹5 crore in recent guidance) must register B2B invoices on a government portal and get an Invoice Reference Number (IRN).
- E-way bill: required when moving goods worth more than a set value.
- GST and TDS/TCS: some government bodies must deduct a small TDS under GST, and e-commerce platforms collect a small TCS from sellers. Rates and rules change, so check the current notification.
A monthly routine for a small registered business
- By the 10th: check all sales invoices are complete and numbered.
- By the 11th: file GSTR-1 (if monthly).
- After the 14th: open GSTR-2B and match it with purchase records.
- Before the 20th: work out output tax, ITC and reverse charge; file GSTR-3B and pay the balance.
- Keep a copy of all returns and challans.
Exercise: due dates
- A monthly filer's GSTR-3B for September: by what date?
- A QRMP taxpayer's quarterly GSTR-1 for July–September: by what date?
- A return is filed 10 days late with ₹50 a day. What is the late fee (ignore the cap)?
Show answers
1) 20 October. 2) 13 October. 3) 10 × ₹50 = ₹500.
Final quiz
Ten questions across all five GST lessons.
1. Which tax applies to a sale between two states?
Inter-state supplies attract IGST.
2. Most goods and services now fall under which main slabs?
After 22 September 2025, 5% and 18% are the main slabs, with 40% for luxury and sin goods.
3. A shop has ₹45 lakh goods turnover in a normal state. Registration by turnover is needed when it is above…
The general limit for goods is ₹40 lakh, so this shop has crossed it.
4. ₹10,000 + 18% GST. Invoice total?
GST ₹1,800, total ₹11,800.
5. Output tax ₹9,000, ITC ₹6,500. Cash GST payable?
₹9,000 − ₹6,500 = ₹2,500.
6. Which is a blocked ITC?
Free samples are blocked.
7. The usual GSTR-1 due date for a monthly filer is…
11th of the next month.
8. The usual GSTR-3B due date for a monthly filer is…
20th of the next month.
9. Under reverse charge, the tax is paid by…
The buyer pays under RCM.
10. Which document do you use to check ITC available each month?
GSTR-2B is the auto-generated ITC statement.
Glossary
- GST
- Goods and Services Tax on the supply of goods and services.
- CGST / SGST
- Central and State GST charged together on supplies within one state.
- IGST
- Integrated GST on supplies between states and imports.
- GSTIN
- 15-character GST registration number.
- HSN / SAC
- Codes that identify goods (HSN) and services (SAC) and their GST rate.
- Taxable value
- The price before GST.
- ITC
- Input tax credit: GST paid on business purchases, subtracted from GST collected on sales.
- RCM
- Reverse charge mechanism: the buyer pays the GST instead of the seller.
- Composition scheme
- A simple scheme for small businesses with a low flat rate but no ITC.
- GSTR-1
- Return of outward supplies (sales).
- GSTR-2B
- Auto-generated statement of purchase invoices and ITC available.
- GSTR-3B
- Summary return in which tax is paid.
- QRMP
- Quarterly return and monthly payment option for smaller taxpayers.
- E-invoice / IRN
- An invoice registered on a government portal with an Invoice Reference Number, required above a turnover limit.
- E-way bill
- An electronic document for moving goods above a set value.
What next?
- Back to the Finance reference guides to see your progress across both parts.
- Pair these guides with the Everyday skills guides (spreadsheets, email, resume basics).
- Read the official guidance on the GST portal and the Income Tax Department portal.
Learning material for beginners, checked in October 2026. It is not tax or legal advice. GST rates, limits and due dates change, and websites sometimes disagree on details. Always confirm on the GST portal (gst.gov.in) or with a Chartered Accountant or GST practitioner before applying anything in real work. All names and amounts in the examples are made up.