GST (Goods and Services Tax) registration is mandatory for businesses crossing certain turnover thresholds, and for certain categories of businesses regardless of turnover. This guide explains who must register, who should voluntarily register, and what the process looks like.
Who must register for GST?
Category
Threshold
Goods suppliers — normal states
Annual turnover above ₹40 lakh
Service providers — normal states
Annual turnover above ₹20 lakh
Special category states (NE, hills)
Annual turnover above ₹10 lakh
E-commerce sellers (Amazon, Flipkart, Meesho)
Mandatory regardless of turnover
Inter-state suppliers
Mandatory regardless of turnover
Casual taxable persons
Mandatory before commencing supply
Voluntary registration — should you register below the threshold?
Even if your turnover is below the threshold, you may want to register voluntarily if:
Your clients are GST-registered businesses who want to claim ITC on your invoice
You supply to large corporates or government entities who require a GST invoice
You plan to scale above the threshold soon and want to establish compliance early
Documents required
PAN card of the business / proprietor
Aadhaar card of the proprietor / directors / partners
Proof of business address (electricity bill, rent agreement)
Bank account statement (cancelled cheque or first page)
Passport-size photograph of the proprietor / authorised signatory
For companies/LLPs: Certificate of Incorporation, MoA/AoA or LLP Agreement
The registration process
Apply on the GST portal (gst.gov.in) using Form REG-01
Upload all required documents and submit the application
A GST officer reviews the application. They may raise a query (REG-03) within 3 working days
If approved, the GSTIN (15-digit GST Identification Number) is issued within 7 working days
Once registered, you must file GSTR-1 by the 11th and GSTR-3B by the 20th of every month, even for months with zero sales. Missing filings attract ₹20-50/day late fees.
Common mistakes during GST registration
Incorrect business address proof — the address on the utility bill must match the registered address exactly
Using personal bank account instead of business/current account
Selecting wrong business category or HSN/SAC codes
Not registering in every state you supply to (inter-state supplies require separate state registrations)