GST Registration — Complete Process, Documents and Threshold FY 2025-26

GST Registration — Complete Process, Documents and Threshold FY 2025-26

Your obligation to register for GST is triggered the moment your aggregate turnover crosses the applicable threshold — ₹40 lakh for goods, ₹20 lakh for services in most states — or the moment you carry out any activity listed in Section 24 of the CGST Act 2017, regardless of turnover. Once triggered, you must apply before making your first taxable supply above the limit. This guide gives you every threshold, document, portal step, and rejection-prevention tip you need for FY 2026-27, including the biometric verification changes now live pan-India.

Who Is Liable to Register Under GST: The Two-Track Test

GST registration liability falls into two distinct tracks. Most small businesses fall into Track 1; founders who misread Track 2 end up with surprise notices.

Track 1: Threshold-Based Registration

Your requirement to register arises when your aggregate turnover in a financial year crosses the following limits:

*Special category states where the lower threshold applies include Manipur, Mizoram, Nagaland, and Tripura for goods; and the North-Eastern states plus Himachal Pradesh and Uttarakhand for services.

You are required to apply for registration within 30 days of crossing the threshold, and you become liable to collect GST from the date of crossing — not the date of the certificate.

Track 2: Mandatory Registration Under Section 24 (No Threshold)

Several categories of suppliers must register regardless of their turnover. If you fall into any of the following, you are liable from day one of your first supply:

• Inter-state suppliers of taxable goods. Even one rupee of inter-state goods supply triggers this. Note: a separate CBIC notification (No. 10/2017-IT(R)) exempts inter-state service suppliers whose aggregate turnover does not exceed ₹20 lakh — so a freelance consultant billing a client in another state is not automatically in this bucket.
• E-commerce operators required to collect Tax Collected at Source (TCS) under Section 52.
• Persons selling through e-commerce operators where the operator is required to collect TCS — this covers every Flipkart or Amazon seller, regardless of turnover.
• Casual taxable persons — anyone making taxable supplies in a state where they have no fixed place of business (e.g., exhibiting at a trade fair in another state).
• Non-resident taxable persons.
• Persons liable to pay tax under Reverse Charge Mechanism (RCM) — if you purchase from an unregistered dealer and the supply attracts RCM, you need a GSTIN.
• Input Service Distributors (ISD).
• Persons required to deduct TDS under Section 51 — typically government entities and notified persons.

How Aggregate Turnover Is Calculated — and Why It Catches People Out

Aggregate turnover is defined under Section 2(6) of the CGST Act as the aggregate of:

1. All taxable supplies (excluding supplies on which GST is paid under RCM by the recipient)
2. Exempt supplies
3. Export of goods or services
4. Inter-state supplies of persons having the same PAN

All of the above is computed on a pan-India PAN basis, excluding CGST, SGST, IGST, UTGST and cess.

Three traps to watch for:

Exempt income counts. Interest income, rental income from residential property, and agricultural produce all form part of aggregate turnover even though they are GST-exempt. A doctor earning ₹18 lakh from medical services (exempt) plus ₹4 lakh from renting clinic equipment (taxable) has an aggregate turnover of ₹22 lakh — above the ₹20 lakh threshold.

It is pan-India, not per-state. A proprietor running a trading business in both Delhi and Mumbai under the same PAN cannot split turnover between states to stay below the threshold. Both rolls up into one aggregate.

Inward RCM supplies are excluded from the calculation. If you pay GST under reverse charge on your purchases, that amount does not inflate your aggregate turnover.

Voluntary Registration: When Registering Below the Threshold Is the Smarter Call

You can apply for GST registration voluntarily under Section 25(3) even if your turnover is zero. This is not just an option for ambitious startups — for several business models, it is the strategically correct call.

Register voluntarily if:

• Your customers are B2B buyers who need to claim Input Tax Credit (ITC) on your invoices. Without a GSTIN, your invoice is dead wood for their ITC claims, making you less competitive than a registered peer.
• You supply to e-commerce platforms that require a GSTIN for seller onboarding, regardless of your scale.
• You intend to export goods or services and wish to file a Letter of Undertaking (LUT) to supply without payment of IGST.
• You are taking on government contracts where a GSTIN is a pre-condition for empanelment.
• You are in a high-growth phase and expect to cross the threshold mid-year — registering now avoids the scramble of applying mid-business-cycle.

The obligation that comes with it: Voluntary registration means full GST compliance from day one — monthly or quarterly GSTR-1, GSTR-3B, annual return, and potential audit. Do not register voluntarily if you are a pure B2C local retailer with no near-term scale ambition; the compliance cost will exceed the benefit.

Documents Required: A Category-Wise Checklist

Prepare these before you open the portal. Uploading incomplete or low-quality documents is the single biggest cause of delay.

Proprietorship

• PAN of the proprietor
• Aadhaar of the proprietor (for OTP-based authentication)
• Passport-size photograph of the proprietor
• Proof of principal place of business: electricity bill / property tax receipt / rent agreement not older than 60 days + NOC from owner if rented
• Bank account: cancelled cheque or first page of passbook showing account number, IFSC and account holder name
• Aadhaar-based EVC (no DSC required for sole proprietors)

Partnership Firm / LLP

• PAN of the firm / LLP
• Partnership deed / LLP Agreement / Certificate of Incorporation (LLP)
• PAN and Aadhaar of all partners / designated partners
• Photograph of authorised signatory
• Proof of place of business (same as above)
• Bank details in the firm's/LLP's name
• Class 3 DSC of any one designated partner (mandatory for LLPs)

Private Limited Company / One Person Company

• PAN of the company
• Certificate of Incorporation (CoI) issued by MCA
• Memorandum and Articles of Association
• PAN and Aadhaar of all directors
• Board resolution authorising the signatory
• Photograph of authorised signatory (director or authorised representative)
• Proof of registered office / place of business
• Bank details in the company's name
• Class 3 DSC of the authorised director (mandatory)

Portal file specifications you must meet: Photographs must be JPEG, less than 100 KB. Documents can be JPEG or PDF, less than 1 MB each. Blurry scans that are technically within file size but unreadable are rejected without comment — scan at 300 DPI minimum.

Step-by-Step Registration on gst.gov.in (2026 Process)

This is the sequence for a fresh registration under the regular taxpayer category. Follow it in order.

1. Navigate to the portal: Go to unknown node → Services → Registration → New Registration.

1. Part A — OTP verification:
2. Select taxpayer type (Regular, Composition, Casual, etc.)
3. Choose your state and district
4. Enter your PAN, mobile number and email address
5. Two separate OTPs are sent — one to mobile, one to email. Enter both.
6. Your Temporary Reference Number (TRN) is generated. Save it. It is valid for 15 days.

1. Log in with TRN: Return to the New Registration page → click Temporary Reference Number (TRN) → enter TRN + OTP.

1. Part B — Business details (10 tabs to complete):
2. Business Details: Trade name, constitution, district, sector/ward/circle, composition option, date of commencement, date of liability.
3. Promoter/Partners: Add all proprietors/partners/directors with PAN, DIN (for directors), Aadhaar, and photo uploads.
4. Authorised Signatory: Designate one person; upload photo.
5. Principal Place of Business: Full address, proof of business document type, upload document, tick the nature of possession (own/rented/leasehold/shared).
6. Additional Places of Business: Add each branch or warehouse separately.
7. Goods and Services: Add HSN codes for goods or SAC codes for services you supply.
8. Bank Accounts: Upload cancelled cheque or passbook page.
9. Verification: Choose DSC or EVC; click Submit.

1. Download the ARN (Application Reference Number): Immediately after submission, download and store the ARN receipt. The ARN is your proof of application and the reference for all communication with the GST department.

1. Complete Aadhaar authentication: Within the prescribed window after ARN generation, the authorised signatory receives an Aadhaar OTP authentication link. Complete this on the linked mobile number. If authentication fails or is not completed, your application is routed for biometric verification.

1. Biometric verification (if flagged): Visit the designated GST Suvidha Kendra (GSC) with original documents. As of 2026, this facility is operational in all states. The officer captures biometric data and verifies the originals. Failure to attend within the prescribed window can lead to application rejection.

1. GSTIN issuance: If no clarification is sought and authentication is complete, your GSTIN is issued within 7 working days of ARN under Rule 9(1) of the CGST Rules, 2017. If the proper officer seeks clarification, Form GST REG-03 is issued; you must respond via Form GST REG-04 within 7 working days.

Aadhaar Authentication and Biometric Verification: What You Need to Know

CBIC significantly tightened the registration workflow through 2024-25, and in FY 2026-27 the biometric route is live pan-India under Rule 8 of the CGST Rules.

How the system decides: The portal's risk engine flags applications based on parameters including PAN-linked registration history, address risk signals, and Aadhaar linkage mismatches. Flagged applications are automatically diverted to the biometric route — you will not be told why you were flagged.

What to do if you are routed to biometric:

• An SMS/email notification tells you to book an appointment at the nearest GSC.
• Carry original PAN, Aadhaar, and the principal place of business proof.
• Appointment must typically be completed within 15 days of the intimation.
• After biometric capture, the officer completes physical verification of the address proof.

The name mismatch problem: If your PAN and Aadhaar have different name spellings (e.g., "Amit Kumar Sharma" on PAN vs "Ameet K. Sharma" on Aadhaar), Aadhaar OTP authentication will fail. You must correct either document before applying. The UIDAI portal allows minor name correction; for PAN corrections, use the NSDL or UTI portal.

Worked Example: The Cost of Missing the Registration Window

Scenario: Vikram Patel runs a hardware trading business in Surat, Gujarat. His aggregate turnover crosses ₹40 lakh in October 2026. He is aware of the threshold but delays applying because "things are busy." He applies in February 2027 — a delay of approximately 120 days.

Tax liability reconstruction:

During October 2026 to January 2027, Vikram continued billing customers without GST. His sales in this period:

• Monthly average: ₹5 lakh
• 4 months of supplies: ₹20 lakh
• Applicable GST rate on hardware items (assumed 18%): ₹20,00,000 × 18% = ₹3,60,000 GST not charged or paid

Penalty under Section 122(1) of CGST Act:

• 10% of tax due = ₹3,60,000 × 10% = ₹36,000
• Minimum penalty per the Act: ₹10,000
• Applicable penalty: ₹36,000

Interest under Section 50:

• Interest at 18% per annum on ₹3,60,000 for 120 days
• ₹3,60,000 × 18% × 120/365 = ₹21,337

Total unexpected cost of the 120-day delay: Tax arrears + penalty + interest = ₹3,60,000 + ₹36,000 + ₹21,337 = ₹4,17,337

Vikram also faces the risk of parallel SGST liability under Gujarat SGST Act — so the actual exposure is potentially double. Had he applied in October when he crossed the threshold, his cost would have been zero (the GST would simply have been collected from buyers).

Lesson: The 30-day window to apply after crossing the threshold is a hard deadline with real financial consequences. Set a monthly revenue tracker and monitor aggregate turnover from month one.

Common Mistakes That Get Applications Rejected — and How to Fix Them

1. Address proof older than 60 days. The portal rejects utility bills (electricity, water, piped gas) dated more than 60 days before the application date. Check the bill date — not the due date — before uploading. If your bill is stale, use a property tax receipt (no age restriction) or request a fresh bill from the utility provider.

2. Premises ownership mismatch without NOC. If the electricity bill is in a parent's or landlord's name and the business is registered there, you must upload a No Objection Certificate (NOC) signed by the property owner in addition to the utility bill. The NOC should be on plain paper, dated, signed, and ideally notarised.

3. PAN-Aadhaar name mismatch. This is the most common cause of Aadhaar authentication failure. Check both documents before applying. If they differ, the resolution is to correct the discrepancy at source — not to try to work around it on the portal.

4. Wrong taxpayer category selected. Selecting "Composition" when you supply inter-state goods, or selecting "Regular" when you qualify and want Composition, creates compliance mismatches that require cancellation and fresh registration. Read the category definitions carefully; Composition is available only to eligible suppliers with turnover up to ₹1.5 crore (₹75 lakh in NE states) for goods.

5. Blurry or oversized documents. Files uploaded in violation of portal specs (over 1 MB, or JPEG photos over 100 KB) either error on upload or render unreadable by the processing officer. Convert PDFs using Smallpdf or Adobe, and compress images before uploading.

6. Bank account not in the entity's name. For a company or LLP, the bank account submitted must be in the entity's name. Submitting a director's personal account is an instant rejection. Open the firm's current account first; GSTIN can follow.

7. Failing to respond to REG-03 within 7 days. If the proper officer issues a clarification notice in Form GST REG-03, you have 7 working days to respond. Missing this window results in rejection of the application under Rule 9(3), and you must start over with a fresh application.

Composition Scheme vs Regular Registration: A Quick Decision Guide

When your turnover crosses the threshold, you choose between two registration types. This decision affects your return frequency, tax rate, ITC eligibility, and billing format.

Choose Composition if you are a local goods trader or manufacturer with minimal B2B customers (who have no ITC requirement), your margins support paying tax from your pocket, and you want simpler compliance. Choose Regular if any of your customers are GST-registered businesses, you sell inter-state, or you export.

Key Takeaways

• Your GST registration liability arises at ₹40 lakh (goods) or ₹20 lakh (services) for most states, measured on aggregate turnover across all PAN-linked entities and locations — including exempt turnover.
• Section 24 mandates registration for inter-state goods suppliers, e-commerce sellers, RCM payers, casual taxable persons, and others without any turnover threshold.
• You have 30 days from the date of crossing the threshold to apply; taxable supplies made during the gap attract GST, penalties (minimum 10% of tax due), and interest at 18% p.a.
• For FY 2026-27, Aadhaar OTP authentication is mandatory for all new registrations; if it fails, biometric verification at a GST Suvidha Kendra is required — sort name mismatches before applying.
• Address proofs must be no older than 60 days; premises in a third party's name need a signed NOC.
• LLPs and companies require a Class 3 DSC for the authorised signatory — verify DSC validity and the associated mobile number before you sit down to file Part B.
• Voluntary registration is worth it for B2B service providers, exporters, and e-commerce sellers even before the threshold is crossed — but it brings the full return-filing obligation from day one.
• Always respond to Form GST REG-03 (clarification notice) within 7 working days; a missed deadline requires a fresh application from scratch.