GST registration gives your business a 15-digit GSTIN, the right to collect GST from customers and the right to claim input tax credit (ITC) on the GST you pay on purchases. This guide explains who must register, which documents you need and how the process works on the GST portal, as the rules stand in October 2026.
Who must register for GST?
Registration becomes compulsory once your aggregate turnover in a financial year crosses the limit for your type of supply:
- Services: ₹20 lakh (₹10 lakh in special category states).
- Goods: ₹40 lakh in most states, including Karnataka. Special category states and a few others keep ₹20 lakh, and some goods such as ice cream, pan masala and tobacco products are excluded from the higher limit.
Aggregate turnover is counted on a PAN basis across India. It includes taxable, exempt, export and inter-state supplies, but leaves out GST itself and inward supplies on which you pay tax under reverse charge. Crossing the limit even once during the year triggers the requirement.
When you must register whatever your turnover
- Selling goods from one state to another (inter-state supply of goods).
- Selling through e-commerce platforms, and operating an e-commerce platform.
- Casual taxable persons and non-resident taxable persons.
- Persons liable to pay tax under reverse charge.
- Persons who must deduct or collect tax at source under GST.
- Agents who supply on behalf of a principal.
- Input Service Distributors, a requirement in force from 1 April 2025.
- Overseas suppliers of online services to unregistered persons in India.
Voluntary registration
A business below the limit can still register. The main reasons are to claim ITC, to deal with larger customers who insist on GST invoices and to sell across states without restriction. Once registered you must file returns on time even if you make no sales.
Documents you need
- Identity documents of the proprietor, partners or directors, and the business PAN.
- Constitution documents: partnership deed, LLP agreement or certificate of incorporation, as applicable.
- Proof of the business address, such as a rent agreement with a recent utility bill, or a property tax receipt for owned premises. Rented premises also need a consent letter from the landlord.
- Proof of a business bank account, such as the first page of the statement.
- Photographs and an authorisation letter or board resolution for the authorised signatory.
- A mobile number and email address that belong to the taxpayer or the authorised signatory.
Step-by-step process on gst.gov.in
- Part A: enter the business PAN and the contact details of the taxpayer, confirm the verification codes and receive a Temporary Reference Number (TRN).
- Part B: log in with the TRN, fill in the business details, principal place of business, bank details and goods or services supplied, and upload the documents.
- Verification: complete the identity authentication and sign the application using one of the permitted methods. An Application Reference Number (ARN) is issued.
- Officer review: the tax officer examines the application. If more information is needed you receive a notice in Form GST REG-03 and must reply within 7 working days.
- GSTIN issued: once the officer is satisfied, the GSTIN is issued along with the registration certificate. Simple applications often finish within a week or two.
Registration on the government portal is free of charge. A CA charges only for preparing and filing the application.
After you get your GSTIN
- Display the certificate and the GSTIN at your place of business.
- Issue proper GST invoices and keep books of account.
- File your returns every month or quarter. Our guide to GSTR-1 and GSTR-3B explains the due dates.
- If you qualify, consider whether the composition scheme suits you.
What if you do not register?
Supplying goods or services without registration when you are required to register can attract a penalty of 10% of the tax due, subject to a minimum of ₹10,000, and higher penalties where tax evasion is established. You also lose the ITC on your purchases for the period.
Mistakes that delay approval
- Business name or address that does not match the supporting documents.
- Using the mobile number or email of an agent instead of the taxpayer.
- A rent agreement without the consent of the owner, or without a recent utility bill.
- Choosing the wrong constitution type or missing the authorised signatory details.
Need help?
SS Auditors prepares and files GST applications for businesses across Bangalore and answers officer queries until the GSTIN is issued. See our GST registration service or contact us.
Last reviewed October 2026. This article is general information, not advice for your specific case. Rules change, so confirm with a chartered accountant before acting.