Who Must Register — Section 22
Every supplier whose aggregate turnover exceeds Rs. 20 lakh (Rs. 10 lakh for special category states) in a financial year must register within 30 days of crossing the threshold. "Aggregate turnover" includes taxable + exempt + export + inter-state supplies with the same PAN across India.
Compulsory Registration — Section 24 (Regardless of Turnover)
These persons must register even if turnover is BELOW Rs. 20 lakh:
| # | Category | Why Compulsory |
|---|---|---|
| 1 | Inter-state supplier | Any inter-state supply (even Rs. 1) requires registration |
| 2 | Casual taxable person | Temporary supply in a state without fixed place of business |
| 3 | Reverse charge payer | Person required to pay tax under RCM |
| 4 | E-commerce operator | All ECOs (Amazon, Flipkart, Swiggy, Uber) |
| 5 | Supplier through ECO | Persons supplying through ECO (unless notified threshold) |
| 6 | Non-resident taxable person | Foreign entity making taxable supply in India |
| 7 | TDS deductor | Government departments, local authorities, PSUs |
| 8 | Input Service Distributor | Office distributing ITC to branches |
| 9 | Agent of supplier | Person supplying on behalf of another taxable person |
| 10 | Person supplying OIDAR services | Online information/database services from outside India |
Major exemptions from compulsory registration (Notification 10/2017):
(a) Person making inter-state supply of services with aggregate turnover up to Rs. 20 lakh — NOT required to register (since 2019 amendment). This helped freelancers enormously.
(b) Person making inter-state supply of handicraft goods with turnover up to Rs. 20 lakh — NOT required (with specific PAN state conditions).
Registration Process — Section 25
Online application: Form GST REG-01 on gst.gov.in. PAN-based, Aadhaar authentication available for faster processing.
Documents: PAN, Aadhaar, address proof (electricity bill/rent agreement/property tax), bank account details, photograph, constitution document (partnership deed/MOA/AOA).
Timeline: Aadhaar-verified applications: approved within 7 working days (often same day). Non-Aadhaar: 7-30 working days with possible query (REG-03).
Separate registration per state: GST requires separate registration for each state where you have a place of business. A company with offices in Maharashtra, Karnataka, and Tamil Nadu needs 3 GST registrations (3 GSTINs).
GSTIN format: 15-digit number — first 2 digits = state code, next 10 = PAN, 13th = entity count (1 for first registration in that state), 14th = Z (default), 15th = checksum. Example: 27AABCT1234F1Z5 (Maharashtra registration of a company).
Amendment — Section 28
Core fields (need officer approval): legal name, address (principal place of business), addition of state (additional place). Filed through REG-14.
Non-core fields (auto-approved): bank details, authorized signatory, email, mobile, trade name. Filed through REG-14.
Cancellation — Section 29
Voluntary cancellation (REG-16): if turnover falls below threshold, business is discontinued, transferred, or amalgamated. Must file final return (GSTR-10) within 3 months. Must pay tax on closing stock (inputs + capital goods) at applicable rate or ITC claimed, whichever is higher.
Suo-motu cancellation by officer: if taxpayer does not file returns for 6 consecutive months (for regular) or 3 quarters (for composition), or obtained registration by fraud/misrepresentation. Officer issues SCN in REG-17, taxpayer replies in REG-18, officer passes order in REG-19.
Revocation of Cancellation — Section 30
If registration was cancelled by the officer (not voluntary), you can apply for revocation within 30 days of cancellation order (extendable by 30 days by Additional/Joint Commissioner, further 30 days by Commissioner). The catch: you must file ALL pending returns and pay ALL outstanding tax, interest, and late fees BEFORE applying for revocation.
Multiple amnesty schemes have been announced allowing late revocation (beyond 30 days) — check the latest notification. The GST Council has periodically opened windows for revocation of cancelled registrations.