GST Registration Process Online: A Step-by-Step Guide

The GST registration process online runs in two parts on the GST portal: Part A generates a Temporary Reference Number using your PAN, mobile and email, and Part B collects the detailed business information that actually gets you a GSTIN. Most straightforward applications clear within about a week; a growing share of small, low-risk applicants can now clear it in as little as three working days under a newer fast-track rule.

Who must register, and at what turnover

The baseline rule is turnover-based. In most normal-category states, a goods supplier must register once aggregate annual turnover crosses ₹40 lakh, and a services provider once it crosses ₹20 lakh (a handful of states retained a ₹20 lakh threshold for goods too). Special category states — the north-eastern and Himalayan states — generally set lower thresholds, around ₹20 lakh for goods and ₹10 lakh for services, though a few of them opted to raise their goods threshold to ₹40 lakh despite their special-category status.

Turnover is not the only trigger, though. Certain categories must register irrespective of turnover: inter-state suppliers, e-commerce operators, casual taxable persons, non-resident taxable persons, persons liable to pay tax under reverse charge, Input Service Distributors, and TDS/TCS deductors under GST, among others. If you fall into one of these categories, the turnover thresholds above do not apply to you at all — registration is mandatory from the first supply. For how the turnover figure itself is calculated across these thresholds, see our guide to annual aggregate turnover under GST.

Part A: PAN, mobile, email and TRN

Part A of Form GST REG-01 asks for the applicant’s legal name (as per PAN), PAN itself, email address and mobile number. The portal sends separate OTPs to the email and mobile for verification. Once both are confirmed, it issues a Temporary Reference Number (TRN) — a session identifier, not a GSTIN — which is valid for a limited window. You use the TRN to log back in and complete Part B; if the window lapses before you finish, you generally have to start again from Part A.

Part B: business details and documents

Part B is where the actual application gets built. It covers:

• Constitution of business (proprietorship, partnership, company, LLP, and so on)
• Details of promoters or partners, including their own PAN and identity proof
• Principal place of business, with address proof (ownership document, rent agreement, or a consent letter, depending on occupancy)
• Additional places of business, if any, at this stage or added later
• HSN or SAC codes for the goods or services you supply
• Bank account details, with a cancelled cheque or bank statement as proof
• Authorised signatory details and digital signature or e-signature

Every one of these fields feeds directly into the taxpayer record a verification API will later return — legal name, constitution, principal place of business, nature of business activities. Getting Part B accurate at registration time avoids mismatches that show up as red flags to counterparties later.

Aadhaar authentication and the biometric route

Most applicants are offered Aadhaar authentication for the primary authorised signatory during the application — an OTP sent to the Aadhaar-linked mobile number. Completing this generally speeds up processing. Applicants flagged as higher-risk by the portal’s automated checks may instead be routed to biometric Aadhaar authentication and document verification at a GST Suvidha Kendra or facilitation centre, which adds a physical verification step and correspondingly more time before approval.

ARN tracking and the officer query cycle

Submitting Part B generates an Application Reference Number (ARN), which you can track on the portal to see where the application stands. From here there are two paths. If the officer is satisfied, registration is granted and a GSTIN is issued. If something needs clarification, the officer issues Form GST REG-03 — a notice seeking additional information or documents, with a fixed window to respond. You reply using Form GST REG-04, attaching whatever was requested. Failing to respond within the given window, or providing an unsatisfactory response, can lead to the application being rejected outright, at which point you would need to file fresh.

The Rule 14A fast-track for small, low-risk applicants

Rule 14A, inserted into the CGST Rules with effect from 1 November 2025 alongside the risk-based automated grant mechanism in Rule 9A, gives small applicants an optional faster path. It applies to applicants whose expected monthly output tax liability on B2B supplies to registered persons — CGST, SGST/UTGST, IGST and cess combined — does not exceed ₹2.5 lakh a month (B2C liability is excluded from that calculation). Under this route, Aadhaar authentication of the primary authorised signatory and at least one promoter or partner is mandatory (OTP-based, or biometric if the system flags higher risk), and registration can be granted within 3 working days of ARN generation once verification and the automated risk check both clear.

This route is optional, not mandatory — an applicant who prefers the standard process, or does not meet the eligibility test, simply goes through the regular Part A/Part B flow described above.

Common reasons registration gets rejected

Most rejections trace back to inconsistency rather than ineligibility:

• Name or address on supporting documents not matching what was typed into the form
• Address proof that does not clearly establish the applicant’s right to operate from that premises
• Blurry, cropped, or non-compliant photographs of promoters/signatories
• Missing or inconsistent bank account proof
• Incomplete responses, or no response, to a REG-03 query within the deadline

Once a GSTIN is finally issued, it is worth verifying it immediately, and periodically afterward — a GSTIN’s status can change later through cancellation or suspension, and current status is not something the registration certificate itself tells you months down the line. See GST cancellation and revocation explained for what that looks like from the other end.

You can verify any GSTIN’s current status, registration date and full profile with a single call:

GET https://gstinapi.com/api/get-taxpayer-info/27AAACR5055K1Z7
X-API-Key: YOUR_API_KEY

Frequently asked questions