A SaaS founder in Salt Lake Sector V once told us he had nothing to file because he had nothing to bill. His company was four months old, revenue was zero, and his GST portal login sat unused. What he did not know was that late fees on unfiled nil returns tick at ₹20 a day, per return, from the first missed date. By the time his first invoice went out, the arrears had grown teeth and a system notice was waiting in his inbox.
That story repeats across Kolkata every month, from Gariahat boutiques to Howrah fabrication units. The return forms themselves are national, and our complete GST return filing guide for India explains each of them in detail. This page covers the layer that changes because your business sits here: who handles your file, the deadlines that bite, what filing costs, and the West Bengal obligations that travel alongside GST.
Do you actually have to file returns for a Kolkata GSTIN?
Yes, from the month registration is granted. The obligation attaches to the GSTIN itself, not to your first sale. In West Bengal the registration thresholds are ₹40 lakh turnover for goods and ₹20 lakh for services, yet many Kolkata firms register voluntarily below those lines to bill corporate clients or sell on marketplaces. Voluntary or not, once the number is live you owe a return for every single period.
Regular taxpayers file GSTR-1 and GSTR-3B. Composition dealers pay quarterly through CMP-08 and file GSTR-4 once a year. A month with zero billing still needs a nil return, which is exactly the trap our Sector V founder walked into.
How does the monthly cycle run for a Kolkata business?
Handled properly, GST filing becomes a quiet routine instead of a recurring panic. The cycle we run for Kolkata clients looks like this:
- You send the previous month's sales and purchase records in the first few days, ideally by the 5th.
- Your CA prepares GSTR-1 and files it before the 11th, so your buyers see their credit on time.
- When GSTR-2B is generated around the 14th, we match it line by line against your purchase register.
- You approve a short summary, we file GSTR-3B by the 20th, and acknowledgements reach you the same day.
Mismatches get flagged before filing, not after a notice arrives. If a supplier has not uploaded an invoice, you hear about it by the 15th, while there is still time to pick up the phone.
Who is the officer behind your GST file in Kolkata?
Every Kolkata GSTIN is allotted at registration either to a West Bengal State GST officer or to a Central GST officer in the Kolkata CGST zone. The state side is administered by the Directorate of Commercial Taxes, which operates from the state commercial taxes directorate in the Beliaghata area and runs wbcomtax.gov.in. Central files move through the central GST commissionerates in Kolkata.
The allotment matters because that officer can seek clarifications and order physical verification of your principal place of business. Verification is where rented Burrabazar gaddis and shared Sector V offices stumble: the rent agreement is informal, the signboard is missing, or the electricity bill carries another name. We build the address proof file before anyone thinks of knocking.
What will monthly filing cost you?
LegalX India files GSTR-1 and GSTR-3B from ₹299 a month for a Kolkata business with a straightforward invoice flow. Your CA confirms the exact fee on a free consultation call once your transaction volume is clear. The portal itself charges nothing; the government fee for filing is nil.
Weigh that against what skipping a filing costs:
- ₹50 a day in late fees per delayed return, ₹20 a day for nil returns.
- Interest at 18 percent a year on any tax paid late.
- Input credit denied when claims do not match GSTR-2B.
- Suspension of the GSTIN itself if returns stay pending, which halts tax invoicing entirely.
Which deadlines belong on your Kolkata office calendar?
Pin this table near the billing desk. The dates hold even through Puja season, when the city's attention is anywhere but tax.
| Return | Due date | Late fee once missed |
|---|---|---|
| GSTR-1 monthly | 11th of the next month | ₹50 a day, ₹20 if nil |
| GSTR-3B monthly | 20th of the next month | ₹50 a day plus 18 percent interest on unpaid tax |
| GSTR-1 under QRMP | 13th after the quarter ends | ₹50 a day, ₹20 if nil |
| CMP-08 for composition dealers | 18th after the quarter ends | Interest on the unpaid amount |
| GSTR-9 annual | 31 December of the next financial year | ₹200 a day up to a turnover linked cap |
Exporters get no relief from this calendar. A tea merchant near Dalhousie shipping under LUT still reports every consignment in GSTR-1 as a zero rated supply, and his refunds move only as fast as his filings do.
What does your CA need from you each month?
Less than most owners fear. One clean folder covers it:
- Sales invoices or a sales register for the month, with e-invoice data where applicable.
- Purchase bills, plus any debit or credit notes issued.
- Details of advances, exports, or reverse charge supplies, if any.
- Portal credentials, or simply the OTP at filing time.
- A bank statement only when a specific query needs tracing.
First timers in Kolkata usually spend 15 minutes assembling this. By the second month it is a habit that takes five.
Where does West Bengal professional tax fit in?
GST is the tax everyone watches; professional tax is the one that catches Kolkata employers off guard. West Bengal levies it under the State Tax on Professions, Trades, Callings and Employments Act, 1979. Delhi and several other states have no such levy, which is why national tax guides barely pause on it.
Two distinct obligations exist. An employer needs a registration certificate to deduct and deposit the tax for staff. A self employed trader or professional needs an enrolment certificate in his own name. profession tax here tops out at ₹2,500 a year per person, and the salary slabs peak at ₹200 a month. Payments run on the West Bengal profession tax portal, and enrolled persons clear their dues by the annual due date.
Several of our GST clients first heard of PT from a notice rather than from their accountant. Since both taxes draw on the same payroll and billing data, we track the two calendars together for every Kolkata retainer client.
Why do Kolkata businesses hand their returns to LegalX India?
Partly because a single missed date costs more than a year of our fees, and partly because we sit where you do. LegalX India works from 58B, Bidhan Park, Taki Road, Barasat, Kolkata 700124, and the whole engagement runs online with a team of 50+ CAs and CSs.
You deal with a named CA, not a ticket queue. Draft returns come to you for approval before submission, acknowledgements land the same day, and a call to +91 96356 85435 brings a callback within 30 minutes. Whether you invoice from Sector V or trade out of Burrabazar, the GST month can close on the 20th without you thinking about it once.