Understanding when you need GST registration, how to apply, and what compliance obligations come with it — all in one comprehensive guide.
When Do You Need GST Registration?
GST registration is mandatory when your aggregate annual turnover exceeds the applicable threshold: ₹40 lakh for businesses supplying goods (₹20 lakh for special category states — Manipur, Mizoram, Nagaland, Tripura, Meghalaya, Himachal Pradesh, and now most northeastern states are at ₹20 lakh for services). For service providers, the threshold is ₹20 lakh (₹10 lakh for special category states).
However, several categories of businesses must register for GST regardless of turnover: businesses making inter-state supplies (selling goods or services across state borders), e-commerce operators and businesses selling through e-commerce platforms (Amazon, Flipkart, etc.), businesses required to pay tax under reverse charge mechanism, input service distributors, casual taxable persons, and businesses making non-resident taxable supplies.
Voluntary registration is advisable even below the threshold if you are a B2B business (your clients can claim input tax credit on your invoices only if you are GST registered), if you are purchasing significant amounts from GST-registered suppliers and want to claim ITC, or if having a GST number enhances your business credibility with larger clients.
The GST Registration Process
The registration process is entirely online on the GST portal (gst.gov.in). Step 1: Create a temporary reference number (TRN) by submitting your PAN, email, and mobile number. Step 2: Complete Part B of the application — business details, nature of business, principal place of business, bank account, and required documents.
Documents required: PAN card, Aadhar card, bank account details (cancelled cheque or bank statement), address proof for business premises (utility bill, rental agreement with ownership proof if rented), constitution proof (partnership deed for partnership, incorporation certificate for companies), photos of authorised signatory, and digital signature.
After submission, you receive an Application Reference Number (ARN). The GST officer reviews the application and may request additional documents or a site inspection. Upon approval, your GSTIN (15-digit GST Identification Number) is issued, typically within 7-14 working days of complete application submission.
GST Compliance — What You Must Do After Registration
GSTR-1 (Outward Supply Return): file monthly (by 11th of following month) if annual turnover exceeds ₹5 crore, or quarterly under the QRMP (Quarterly Return Monthly Payment) scheme if turnover is below ₹5 crore. Includes all B2B and B2C sales invoices.
GSTR-3B (Summary Return with Tax Payment): monthly filing with self-assessed tax payment, due by the 20th of the following month (or 22nd/24th for certain taxpayers under QRMP). This is where you declare your net tax liability and pay the balance after ITC.
Annual Return GSTR-9: due by December 31 of the following financial year. Reconciles your annual outward and inward supplies, ITC claimed, and taxes paid. Mandatory for businesses with turnover above ₹2 crore; optional for smaller businesses (but recommended for ITC reconciliation).
Frequently Asked Questions
Can I claim input tax credit from day one of GST registration?
Yes. From the date of GST registration, you can claim ITC on purchases from GST-registered suppliers where GST has been charged. For opening stock (goods held in stock on the registration date), a special ITC claim is available for goods purchased within 1 year before registration. Submit Form GST ITC-01 within 30 days of registration to claim this opening stock ITC — it is a significant benefit that many new registrants miss.
What are the penalties for late GST filing in India?
Late filing attracts: late fees of ₹50 per day (₹20 per day for nil returns) under CGST and equivalent under SGST, capped at ₹5,000 per return. Additionally, interest at 18% per annum applies on unpaid tax from the due date. The combination of late fees and interest can add up quickly for businesses that consistently miss deadlines — set calendar reminders for the 11th (GSTR-1) and 20th (GSTR-3B) of each month.
Do I need a separate GST registration for each state where my business operates?
Yes. GST is state-specific — if your business has a physical presence (office, godown, warehouse, or supply operations) in multiple states, you require a separate GSTIN for each state. Inter-state supplies without establishment in the destination state do not require additional registration, but once you have a permanent establishment (office, warehouse), registration in that state is mandatory.