GST registration gives your business a 15-character Goods and Services Tax Identification Number (GSTIN). It is compulsory once your turnover crosses the threshold, and from day one for some businesses whatever their turnover. The application on gst.gov.in is free, and the whole process is online.
This guide covers who must register, the documents by entity type, the Part A and Part B mechanics on the portal, Aadhaar authentication, the Rule 14A three-working-day route, HSN and SAC codes, the reasons applications get rejected and what you owe once the GSTIN is issued. If you would rather hand it over, Regikart's CAs handle GST registration end to end.
Quick answers
- Threshold: ₹40 lakh aggregate turnover for goods, ₹20 lakh for services; ₹20 lakh and ₹10 lakh in special category states (section 22 of the CGST Act).
- Compulsory regardless of turnover: inter-state suppliers of goods, e-commerce sellers of goods, casual and non-resident taxable persons, reverse charge, ISD, TDS/TCS, OIDAR and agents (section 24).
- Deadline: apply within 30 days of becoming liable (section 25).
- Government fee: none.
- Fast route: under Rule 14A, a supplier whose output tax to registered persons stays within ₹2.5 lakh a month gets registration within 3 working days of Aadhaar authentication.
- Forms: REG-01 application, ARN on submission, REG-03 query, REG-04 reply, REG-06 certificate.
- Rates now: since 22 September 2025 the main GST slabs are 5% and 18%, with 40% for demerit goods.
What GST registration gives you
Once registered, a business can legally collect GST from customers, claim input tax credit on purchases and file GST returns. A GSTIN is essential for:
- Issuing tax-compliant invoices
- Claiming input tax credit (ITC)
- Selling on e-commerce platforms
- Winning contracts with larger, GST-registered clients who require compliant vendors
Who needs to register
The turnover thresholds
Under section 22, registration becomes compulsory once aggregate turnover in a financial year crosses the threshold. If you want full input tax credit and no limits on who you sell to, this is regular GST registration.
| Who | Threshold for compulsory registration |
|---|---|
| Goods suppliers | Over ₹40 lakh (₹20 lakh in special category states) |
| Service providers | Over ₹20 lakh (₹10 lakh in special category states) |
| Inter-state suppliers of goods | No threshold, compulsory from day one |
| E-commerce sellers of goods (Amazon, Flipkart and similar) | No threshold, compulsory |
| Casual and non-resident taxable persons, ISD, TDS/TCS, OIDAR, agents, reverse charge | No threshold, compulsory (section 24) |
Compulsory registration regardless of turnover (section 24)
Section 24 lists the businesses that must register whatever their turnover. Each has its own registration type:
- Inter-state suppliers of goods, and persons liable to pay tax under reverse charge.
- Suppliers of goods through e-commerce platforms, and the operators themselves: see GST for an e-commerce operator.
- Occasional sellers at exhibitions or events in another state: GST registration for a casual taxable person.
- Foreign businesses supplying in India without a fixed place here: GST for a non-resident taxable person.
- Head offices distributing input credit to branches: GST input service distributor.
- Government deductors and e-commerce collectors: GST TDS and TCS registration.
- Foreign providers of online information and database access services: GST OIDAR registration.
- Agents supplying on behalf of others. Units in special economic zones register separately too: see GST for an SEZ unit.
Crossing the threshold mid-year: 30 days to apply
Under section 25, you must apply within 30 days of the date you become liable to register. For a turnover-based liability, that is the date your aggregate turnover crosses the threshold, not the end of the year.
Voluntary registration below the threshold
You can register voluntarily below the threshold. It is worth doing if you want to claim input tax credit, sell to B2B customers who insist on a GSTIN, or expand inter-state. Small businesses that sell mostly to consumers can look at the GST composition scheme: the limit is ₹1.5 crore for goods (₹75 lakh in special category states) and ₹50 lakh for services, with tax at 1%, 5% or 6% of turnover, but no input tax credit and no inter-state sales of goods.
The Rule 14A three-day route for small suppliers
Rule 14A of the CGST Rules came in through Notification 18/2025-Central Tax dated 31 October 2025, effective 1 November 2025. It is not a separate scheme: it is a faster door into regular registration.
You declare that the output tax on your supplies to registered persons will not exceed ₹2.5 lakh a month. Registration is then granted within 3 working days of successful Aadhaar authentication. Sales to consumers do not count towards the limit. At 18%, ₹2.5 lakh of output tax is roughly ₹13.9 lakh of B2B sales a month.
It suits retailers, restaurants, consumer brands and small B2B suppliers. If your sales to businesses are likely to grow past that level, you can leave the route by filing Form GST REG-32, and the officer's order comes in REG-33. We check your projected B2B sales before choosing the route.
Documents required, by entity type
The exact documents depend on your business structure. Below is a quick reference.
| Business type | Key documents required |
|---|---|
| Sole proprietor | PAN and Aadhaar of the proprietor, photograph, business address proof, bank details |
| Partnership firm | Partnership deed, PAN of the firm, partners' PAN, Aadhaar and photographs, address proof |
| LLP | LLP agreement and incorporation certificate, PAN of the LLP, designated partners' PAN and Aadhaar, address proof |
| Private limited or public company | Certificate of Incorporation, PAN of the company, MOA and AOA, directors' PAN and Aadhaar, board resolution appointing the authorised signatory |
| Trust or society | Trust deed or registration certificate, PAN of the entity, trustees' or office bearers' PAN and Aadhaar |
| All types | Proof of principal place of business, and a Class 3 digital signature for companies and LLPs |
Address and signatory proofs
- Owned premises: an electricity bill or property tax receipt, not older than two months.
- Rented premises: the rent agreement plus a no-objection letter from the owner, with the owner's utility bill.
- The legal name must match the PAN exactly, and the signatory's Aadhaar name must match their PAN.
- Passport-size photographs of the proprietor, partners or directors.
Fees
There is no government fee for GST registration. The same is true for amending a registration (REG-14), cancelling it (REG-16) or applying to revoke a cancellation (REG-21).
You pay only a professional fee if a CA files it for you. Regikart's fee is ₹1,499 for regular GST registration, and ₹999 for regular registration under the Rule 14A route, composition, casual taxable person, non-resident, e-commerce operator and ISD registrations. TDS/TCS, OIDAR and SEZ registrations are ₹1,499.
The registration process on gst.gov.in
Part A and the TRN
On gst.gov.in, go to Services, Registration, New Registration. Part A asks for the legal name exactly as per PAN, the PAN, the state, and a mobile number and email for the primary authorised signatory. After both OTPs are verified you get a Temporary Reference Number (TRN), valid for 15 days. Part B must be completed within that window or you start again.
Part B: business, promoters, signatory, premises, bank, HSN/SAC
Log back in with the TRN and complete Part B of Form GST REG-01. It covers:
- Business details: trade name, constitution, date of commencement, reason for registration.
- Promoters, partners or directors, with their PAN, Aadhaar and photograph.
- The authorised signatory, with proof of appointment.
- The principal place of business and any additional places of business in the same state.
- The goods and services you supply, with HSN or SAC codes.
- Bank account details, if available at this stage.
Documents are uploaded as PDF or JPEG within the portal's size limits. A blurred scan or a proof in the wrong name is one of the commonest reasons for a query.
Aadhaar authentication, and what happens if it fails
Under Rule 8(4A), the applicant and key persons authenticate Aadhaar, usually by OTP on the Aadhaar-linked mobile. This is the step that decides whether registration takes days or weeks. If the portal flags the application, you get an appointment for biometric authentication and document verification at a GST Suvidha Kendra. If Aadhaar is not authenticated, the application goes to physical verification of the premises under Instruction 03/2025 of 17 April 2025, which takes longer.
DSC or e-sign, by entity type
Companies and LLPs must sign with a Class 3 digital signature certificate. Proprietors, partnership firms and other applicants may sign with Aadhaar e-sign or EVC.
ARN, officer review, REG-03 query and REG-06 certificate
On submission, the portal generates an Application Reference Number (ARN). You can track it under Services, Registration, Track Application Status. The officer either approves the application or issues a query in Form GST REG-03, which you answer in REG-04 within the time the portal gives you. If a query is complex, a GST notice reply prepared by a CA saves a rejection. Once approved, the certificate is issued in REG-06 and can be downloaded under Services, User Services, View or Download Certificates. Display it at your place of business.
Getting the HSN and SAC codes right
HSN codes classify goods and SAC codes classify services. Selecting codes that do not match your activity is one of the most common reasons an application is queried or rejected. Pick codes that genuinely describe what you sell, and add the ones you realistically use rather than a long list.
The minimum number of HSN digits you must use depends on your aggregate turnover, and the bands are set by notification. We check your codes and the digit level against the current notification before filing.
Timeline
| Route | Timeline | Basis |
|---|---|---|
| Rule 14A | Within 3 working days of successful Aadhaar authentication | Legal position, Rule 14A |
| Ordinary registration, clean file, Aadhaar authenticated | Usually 5 to 7 working days | Regikart's experience, not a statutory period |
| Query raised, biometric appointment or physical verification | Longer, depending on the officer and your reply | Varies |
There is no fixed statutory day count we would quote for ordinary registration. What moves it fastest is a clean file: names matching PAN, current address proof, correct codes and Aadhaar authenticated on the first attempt.
Common reasons for rejection
- Business name not matching the PAN exactly.
- Aadhaar authentication failing because the Aadhaar name does not match the PAN.
- HSN or SAC codes that do not match the actual business activity.
- Address proof older than two months, or a rent agreement without the owner's no-objection letter.
- Bank account inactive, or details entered incorrectly.
- Constitution type not matching the documents uploaded.
- A director without an active DIN: see our guide to DIR-3 KYC.
- Not answering the REG-03 query in time.
Multiple GSTINs: one per state per PAN
GST registration is state-wise. You take one GSTIN in each state where you make taxable supplies, all under the same PAN. Within a state, you may take a separate registration for each place of business (section 25(2), and Rule 11 as substituted from 1 February 2019), but you cannot have one place on composition and another on normal tax. Supplies between your own registrations need tax invoices, because each GSTIN is a distinct person under GST.
After you get your GSTIN
Switch to GST-compliant invoices, and update your GSTIN on your website, letterhead and marketplace accounts.
The returns you now owe
| Return | What it covers | Due date |
|---|---|---|
| GSTR-1 | Outward supplies | 11th of the next month (13th after the quarter under QRMP) |
| GSTR-3B | Summary return and tax payment | 20th of the next month; 22nd or 24th after the quarter under QRMP, by state |
| CMP-08 | Composition tax payment | 18th after the quarter |
| GSTR-4 | Composition annual return | 30 June |
| GSTR-9 | Annual return, mandatory above ₹2 crore aggregate turnover | 31 December |
Our team handles GST return filing and the GSTR-9 annual return. The GSTR-1 and GSTR-3B guide covers the monthly cycle in detail. File nil returns on time too: late returns attract late fees and interest, and persistent non-filing can lead to suspension or cancellation.
ITC reconciliation against GSTR-2B
Reconcile your purchase register against GSTR-2B every month before filing GSTR-3B. Credit you claim that is not in 2B is the most common trigger for a notice. See our GST input tax credit reconciliation guide.
E-invoicing above ₹5 crore
If your aggregate turnover exceeds ₹5 crore in any financial year, B2B invoices must be reported to the Invoice Registration Portal. See GST e-invoicing.
The bank account requirement after registration
A bank account is not a precondition for applying. The bank account details are furnished on the portal after registration. Open a current account in the business name and add it promptly once the GSTIN is issued.
If you do not register when required
- Penalty under section 122: 10% of the tax due or ₹10,000, whichever is higher. For deliberate evasion, 100% of the tax due.
- Interest under section 50(1): 18% a year on tax paid late.
- Tax without credit: you pay the tax for the unregistered period out of pocket, and customers cannot claim credit on invoices you could not issue.
What GST 2.0 changed
From 22 September 2025, the main GST slabs are 5% and 18%, with 40% for demerit goods. The 12% and 28% slabs have largely been removed. When you pick HSN or SAC codes, check the current rate for each: an old rate chart will be wrong for most items.
Get your GSTIN without the back and forth
Regikart's CAs check your documents, choose the route (regular, Rule 14A or composition), select the codes, file REG-01, guide Aadhaar authentication and answer any query. We serve 250+ clients from Kolkata (head office), Delhi and Bengaluru. Start your GST registration, or call or WhatsApp +91 70444 94804, or contact us.
Frequently asked questions
What is the turnover threshold for GST registration?
₹40 lakh aggregate turnover for goods suppliers and ₹20 lakh for service providers. In special category states the limits are ₹20 lakh and ₹10 lakh. Inter-state suppliers of goods and e-commerce sellers of goods must register regardless of turnover.
Is GST registration free?
Yes. The government charges no fee for GST registration. You pay only a professional fee if a CA files it for you: Regikart charges ₹1,499 for regular registration and ₹999 under the Rule 14A route, plus GST at 18%.
How long does GST registration take?
Under Rule 14A, within 3 working days of successful Aadhaar authentication. For ordinary registration there is no day count we would quote; in our experience a clean, Aadhaar-authenticated application is usually approved in 5 to 7 working days. Queries or physical verification take longer.
What is Rule 14A?
A faster route to regular registration, in force since 1 November 2025. If the output tax on your supplies to registered persons will not exceed ₹2.5 lakh a month, registration is granted within 3 working days of Aadhaar authentication. You can leave the route through REG-32.
What if I cross the threshold mid-year?
You must apply within 30 days of the date you become liable to register, under section 25. For a turnover-based liability, that is the date your aggregate turnover crosses the threshold.
Can I have multiple GSTINs on one PAN?
Yes, one per state. If you supply from several states, you take a separate GSTIN in each, all under the same PAN. Within one state you may also take separate registrations for different places of business.
Do I need a current account to register?
Not to apply. Bank details are furnished on the portal after registration. A current account in the business name is standard for a business, so open one early and add it promptly once the GSTIN is issued.
Is GST mandatory for Amazon and Flipkart sellers?
Yes. Suppliers of goods through e-commerce platforms must register regardless of turnover.
What happens if Aadhaar authentication fails?
You may be given an appointment for biometric authentication at a GST Suvidha Kendra. If Aadhaar is not authenticated at all, the application goes to physical verification of your premises, which takes longer.
What is the penalty for not registering?
10% of the tax due or ₹10,000, whichever is higher, under section 122, rising to 100% for deliberate evasion, plus interest at 18% a year under section 50(1) on the tax paid late.
Can I register voluntarily below the threshold?
Yes. Voluntary registration lets you claim input tax credit and invoice B2B clients who insist on a GSTIN. Once registered, you must file returns like any other registered person.
GST registration ke liye kaunse documents chahiye?
Business ka PAN, promoter ya authorised signatory ka PAN, Aadhaar aur photo, principal place of business ka address proof (do mahine se purana nahi), aur entity ke constitution documents jaise partnership deed ya Certificate of Incorporation. Company aur LLP ko Class 3 DSC bhi chahiye.
About the author
CA Deepak Jaiswal
Founding Partner, FCA at Regikart. Want to discuss this in the context of your business?
