GST registration is the single most important indirect tax compliance for any business operating in India. It is the gateway to legally collecting tax from customers, claiming input tax credit on purchases, selling across state lines, and participating in e-commerce marketplaces. Without a valid GSTIN, a business cannot issue GST-compliant invoices-which means every B2B customer is immediately at a disadvantage because they cannot claim ITC on purchases from you.
This guide covers every aspect of GST registration: who must register (mandatory categories), who should register (voluntary advantages), the threshold limits by state, the step-by-step portal process, documents for every entity type, the composition scheme option, post-registration compliance obligations, and the 2026 changes that affect new registrations. For businesses exploring GST registration services (know more), this guide provides the knowledge to make informed decisions about timing, structure, and compliance.
Turnover Thresholds: When GST Registration Becomes Mandatory
| Category | Normal States | Special Category States | Composition Scheme |
|---|---|---|---|
| Goods suppliers | Aggregate turnover > Rs 40 lakh | Aggregate turnover > Rs 20 lakh | Up to Rs 1.5 crore |
| Service providers | Aggregate turnover > Rs 20 lakh | Aggregate turnover > Rs 10 lakh | Up to Rs 50 lakh |
| Mixed suppliers (goods + services) | Higher of applicable limits based on predominant supply | Lower of applicable limits | Up to Rs 50 lakh |
Special category states: Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagaland, Puducherry, Sikkim, Telangana, Tripura, Uttarakhand. Note: Assam and Jammu & Kashmir have opted for the higher Rs 40 lakh limit despite being special category states.
How aggregate turnover is calculated: It includes all taxable supplies + exempt supplies + exports + interstate supplies, calculated on PAN basis across India (all branches under one PAN are counted together). It excludes GST itself (CGST, SGST, IGST, compensation cess).
13 Categories Requiring Mandatory Registration (Section 24)
Even if your turnover is below the threshold, registration is mandatory if you fall in any of these categories:
- Interstate suppliers: Any business supplying goods or services across state borders-even Rs 1 of interstate supply triggers mandatory registration.
- E-commerce sellers: Sellers on Amazon, Flipkart, Meesho, or any e-commerce platform must register regardless of turnover.
- E-commerce operators: Platforms facilitating supply (marketplace operators).
- Persons liable to pay tax under reverse charge: When the recipient pays GST instead of the supplier (e.g., legal services from advocates, director fees).
- Casual taxable persons: Temporary operators at trade fairs, exhibitions, stalls.
- Non-resident taxable persons: Foreign entities supplying in India.
- Input Service Distributors (ISD): Entities distributing ITC to branches.
- TDS deductors under GST: Government entities and specified persons deducting tax at source.
- TCS collectors: E-commerce operators collecting tax at source.
- Persons supplying through e-commerce operators: Suppliers whose tax is collected by the e-commerce operator under Section 9(5).
- OIDAR service providers outside India: Foreign entities providing online information and database access to unregistered persons in India.
- Online money gaming operators outside India: Foreign platforms providing online gaming to persons in India.
- Agents of suppliers/recipients: Persons making taxable supply on behalf of others.
For businesses completing company registration (know more) with interstate or e-commerce business plans, GST registration should be obtained immediately after incorporation.
Voluntary Registration: When It Makes Sense
Even if your turnover is below the threshold and you don’t fall in any mandatory category, voluntary registration offers advantages:
| Advantage | How It Helps |
|---|---|
| Input Tax Credit (ITC) claim | Recover GST paid on purchases, rent, services, equipment. Without registration, GST paid on inputs is a cost. |
| B2B credibility | GST-registered suppliers are preferred by registered buyers because buyers can claim ITC on purchases. |
| Interstate supply capability | Without registration, you cannot legally supply across state lines. Registration opens pan-India market access. |
| E-commerce eligibility | Cannot sell on Amazon/Flipkart without GSTIN. Registration is a prerequisite for marketplace onboarding. |
| Government tender participation | Many government tenders on GeM require GSTIN as a mandatory field. |
The trade-off: Once registered (even voluntarily), you must file all GST returns (monthly/quarterly), collect GST from customers, and maintain GST-compliant records. You cannot file NIL returns indefinitely and then claim “below threshold.” Consider this commitment before registering voluntarily. For businesses using professional accounting services (know more), the ongoing GST compliance cost should be factored into the voluntary registration decision.
Documents Required by Entity Type
| Entity Type | Primary Documents | Additional Documents |
|---|---|---|
| Sole Proprietorship | Proprietor’s PAN, Aadhaar, photograph, bank statement/cancelled cheque | Address proof of business (electricity bill, rent agreement, property tax receipt) |
| Partnership Firm | Firm PAN, partnership deed, all partners’ Aadhaar and PAN | Authorised signatory’s details, bank statement, address proof |
| LLP | LLP PAN, LLP Agreement, designated partners’ Aadhaar and PAN | Certificate of Incorporation (LLP), bank statement, address proof |
| Private Limited / Public Company | Company PAN, Certificate of Incorporation, directors’ Aadhaar and PAN, MOA/AOA | Board resolution for authorised signatory, bank statement, address proof |
| HUF | HUF PAN, Karta’s Aadhaar and PAN | Bank statement, address proof of business premises |
| Trust / Society | Entity PAN, registration certificate, authorised person’s Aadhaar and PAN | Trust deed / Society memorandum, bank statement, address proof |
2026 requirement: Valid bank account details must be furnished within 30 days of registration or before filing GSTR-1/IFF (whichever is earlier) to avoid suspension per GSTN advisory dated 20 November 2025. Biometric Aadhaar verification is now required for new registrations per GSTN advisory dated 12 February 2025.
Step-by-Step Registration Process on gst.gov.in
- Visit gst.gov.in and click “Register Now” under “Taxpayers.” Select “New Registration.” This is the ONLY official portal-no fees.
- Part A: Enter PAN, mobile, email. Enter business PAN (entity PAN for companies/LLPs; individual PAN for proprietors). Enter mobile number and email. Receive OTPs on both. Verify. You receive a Temporary Reference Number (TRN).
- Part B: Login with TRN and complete the application. 10 sections: Business Details, Promoter/Partner Details, Authorised Signatory, Place of Business, Goods & Services (HSN/SAC codes), Bank Account, State Specific Information, Aadhaar Authentication, Verification.
- Upload documents. All documents in PDF/JPEG. Photograph of proprietor/partners/directors. Proof of business address (rent agreement + NOC from landlord, or property tax receipt). Bank statement or cancelled cheque.
- Aadhaar authentication and biometric verification. Complete Aadhaar OTP authentication. For new registrations in 2026, biometric verification at a GST Suvidha Kendra may be required based on risk profiling.
- Submit and receive ARN. Application Reference Number (ARN) is generated. Use this to track status. For entities managing income tax return filing (know more), the GSTIN obtained here will be linked to ITR disclosures.
- Officer verification and GSTIN issuance. The GST officer verifies documents and place of business (physical or virtual verification). If approved: GSTIN issued in 2-7 working days. If clarification needed: response required within 7 days.
Composition Scheme: Simplified Compliance for Small Businesses
| Parameter | Regular Registration | Composition Scheme |
|---|---|---|
| Turnover limit | No upper limit | Rs 1.5 crore (goods) / Rs 50 lakh (services & mixed) |
| Tax rate | Standard GST rates (5%, 12%, 18%, 28%) | 1% for manufacturers, 5% for restaurants, 6% for service providers |
| ITC availability | Full ITC available | No ITC. Cannot claim credit on inputs. |
| Interstate supply | Allowed | Not allowed. Intra-state only. |
| Return filing | Monthly/quarterly (GSTR-1, GSTR-3B) | Quarterly (CMP-08) + Annual (GSTR-4) |
| Invoice type | Tax invoice with GST breakup | Bill of Supply (no GST charged separately) |
| E-commerce | Can sell on e-commerce platforms | Cannot sell through e-commerce operators |
Post-Registration: Compliance Calendar
| Frequency | Compliance | Due Date |
|---|---|---|
| Monthly | GSTR-3B (summary return with tax payment) | 20th of following month (QRMP: quarterly) |
| Monthly | GSTR-1 (outward supply details) | 11th of following month (QRMP: 13th of month after quarter) |
| Annual | GSTR-9 (annual return, turnover > Rs 2 crore) | 31 December |
| Annual | GSTR-9C (reconciliation, turnover > Rs 5 crore) | 31 December (self-certified) |
| As applicable | E-invoicing (turnover > Rs 5 crore in 2026) | Real-time (before invoice issuance) |
| Within 30 days | Bank account details update | 30 days from registration or before GSTR-1/IFF |
For businesses using tax audit services (know more), the GST compliance calendar intersects with income tax due dates-both must be tracked together.
What Changed in 2026
- Mandatory 6-digit HSN reporting: All GST-registered businesses must report HSN codes at the 6-digit level on invoices and returns (previously 4-digit for turnover up to Rs 5 crore).
- E-invoicing threshold: Rs 5 crore: Mandatory for all businesses with aggregate annual turnover exceeding Rs 5 crore (progressively lowered from Rs 500 crore in 2020).
- Biometric Aadhaar verification: Per GSTN advisory dated 12 February 2025, new registrations may require biometric verification at GST Suvidha Kendras.
- Bank account 30-day rule: Per GSTN advisory dated 20 November 2025, valid bank account details must be furnished within 30 days of registration to avoid suspension.
- Stricter place-of-business verification: Per CBIC Instruction No. 03/2025-GST dated 17 April 2025, enhanced verification of principal place of business during registration.
- Invoice Management System (IMS): Changes to how invoices are accepted/rejected by recipients, affecting ITC claims.
Common Mistakes to Avoid
Mistake 1: Not registering despite mandatory requirement. Penalty: 10% of tax due or Rs 10,000, whichever is higher. Many businesses don’t realise that even Rs 1 of interstate supply triggers mandatory registration.
Mistake 2: Registering voluntarily without understanding compliance cost. Once registered, you must file returns (even NIL), collect GST, and maintain records indefinitely. The monthly/quarterly compliance cost for a small business is Rs 1,000-3,000 in professional fees. Factor this before registering.
Mistake 3: Wrong HSN/SAC codes. Incorrect classification leads to wrong GST rates, ITC mismatches, and departmental queries. From 2026, all taxpayers must report 6-digit HSN-errors are immediately visible.
Mistake 4: Not furnishing bank details within 30 days. Your GSTIN may be suspended if bank account details are not updated within 30 days of registration. This is a new compliance trap that catches many new registrations.
Mistake 5: Registering as composition when you need interstate supply. Composition scheme dealers cannot make interstate supplies. If your business model involves shipping across states, regular registration is the only option.
Key Takeaways
GST registration is the foundational indirect tax compliance for Indian businesses. The threshold is Rs 40 lakh for goods suppliers and Rs 20 lakh for service providers in normal states, with lower limits in special category states. However, 13 categories (interstate suppliers, e-commerce sellers, reverse charge persons, etc.) must register regardless of turnover under Section 24.
The process is free, online (gst.gov.in), and takes 2-7 working days with correct documents and Aadhaar authentication. The 2026 changes-mandatory 6-digit HSN, e-invoicing at Rs 5 crore, biometric verification, 30-day bank account rule-add new compliance layers that businesses must address from Day 1. The composition scheme (Rs 1.5 crore goods / Rs 50 lakh services, lower rates, no ITC, no interstate supply) is ideal for small intra-state businesses.
Post-registration, the compliance calendar (GSTR-3B monthly/quarterly, GSTR-1 monthly, GSTR-9/9C annual) is ongoing. The cost of compliance should be planned before registration-voluntary registration without a compliance plan leads to suspension, cancellation, and penalties that are harder to resolve than the registration itself.
Get Your GST Registration Right from Day 1
GST registration is free and fast-but the ongoing compliance (returns, ITC reconciliation, HSN reporting, e-invoicing) requires professional support. Getting the registration right from Day 1-correct HSN codes, appropriate scheme choice, proper bank account linkage, and a compliance calendar-prevents the cascade of notices, suspensions, and penalties that follow from a poorly set up GSTIN.
Explore our GST registration services (know more) for end-to-end registration, HSN classification, composition scheme advisory, post-registration compliance setup, and monthly return filing.
For queries, reach out at +91 945 945 6700 or WhatsApp us directly.
