GST registration process in India, step by step: from PAN to GSTIN and your first return

GST registration is a single online application on gst.gov.in that turns your PAN into a 15-character GSTIN for one state. There is no government fee, it is filed in one form — FORM GST REG-01 — and when nothing goes wrong it is done in about a week. Plenty goes wrong, almost always in the same three places: the address documents, Aadhaar authentication, and the reply to the officer’s query.

This guide walks the journey in order, from who must register through to the thirty days after your GSTIN arrives — the stretch where most new registrants quietly slip. It is written for a founder or ops manager doing this themselves, and for anyone supervising a chartered accountant doing it for them. Where a rule comes from the CGST Act, 2017 or the CGST Rules, 2017, the section, rule or form is named. Everything here is as of September 2026.

Who must register, and by when

There are two doors into GST registration: turnover, and what you do.

Door one: the turnover threshold (Section 22)

Registration becomes compulsory when aggregate turnover in a financial year crosses the threshold for your state and what you supply. Aggregate turnover is computed on the PAN across all of India, not per state.

Door two: compulsory registration (Section 24)

Section 24 overrides the threshold entirely. If you fall in one of these categories you register even if your turnover is zero:

• Persons making inter-state supplies of goods.
• Casual taxable persons — occasional supply in a state where you have no fixed place of business. The casual registration guide covers the advance tax deposit and the 90-day validity.
• Persons liable under reverse charge, and non-resident taxable persons.
• E-commerce operators, and persons who supply goods through one.
• Input service distributors, agents, TDS deductors and OIDAR providers.

Inter-state supply of services alone does not trigger Section 24 up to the threshold (Notification 10/2017-Integrated Tax) — a common misunderstanding among consultants and software firms.

Registration is also state-wise (Section 25): one PAN, one registration per state, with extra registrations for separate places of business inside a state optional under Rule 11. Opening in a second state? The second-state checklist covers what changes.

Before you start: the checklist

The TRN expires, so collect everything before you start. The official list is printed in FORM GST REG-01, and CBIC Instruction No. 03/2025-GST dated 17 April 2025 tells officers not to demand anything beyond it.

Scan everything to PDF or JPEG and check the size: the portal prints a limit next to each upload box, typically 100 KB to 1 MB. A 4 MB rent agreement is why people abandon Part B halfway. The document guide has the full list with formats.

Part A: getting your Temporary Reference Number

On gst.gov.in go to Services → Registration → New Registration and fill in:

1. Who is applying. Select “Taxpayer” (or Casual Taxable Person, Tax Deductor and so on), then the state and district. The state decides the first two digits of your GSTIN and cannot be changed later — see the state code table.
2. Legal name and PAN. The name is validated against the PAN database. If it bounces, the fix is at the income-tax end.
3. Email and mobile. Two separate OTPs arrive, each valid ten minutes. Both must be verified.
4. Collect the TRN. A 15-character Temporary Reference Number is generated and sent by email and SMS. It is valid for 15 days.

Nothing is filed yet; the TRN only reserves your application. To continue, return to New Registration, select “Temporary Reference Number”, enter it and pass one more OTP. Your draft sits under My Saved Application with the days remaining.

Part B: every tab in plain words

Part B is a tabbed form. It saves as you go, and will not submit until every tab shows a green tick.

One question deserves care: the composition scheme on the Business Details tab. Answering yes bars you from collecting tax or claiming input credit. If unsure, answer no; you can opt in at the start of a financial year.

The address tab in detail

This tab is short but decides most outcomes. Three things must agree: the typed address, the nature of possession you select, and the document you upload.

Instruction 03/2025-GST is worth knowing by name. It tells officers to work strictly from this list and not to demand the owner’s PAN or Aadhaar, photographs of the premises, original physical copies, or answers to presumptive questions such as why you want to register in that state. Any extra document needs a Deputy or Assistant Commissioner’s approval.

If you have no premises in the state

A virtual office is filed here like any other rented or consent-based premises. It is a real commercial unit whose address you are licensed to use: the provider supplies the agreement in your legal name, the owner’s NOC and a recent utility bill; your name board goes up; staff receive your post and, if it comes to it, the verifying officer. Nothing in the CGST Act requires exclusive occupation, a minimum area, or that anyone sits there daily.

What the law does require is that the premises be genuine. Rule 25 allows physical verification with a report in FORM GST REG-30, and Rule 21 allows cancellation where business is not conducted from the declared place, so the provider must control the unit and show ownership proof for it. SimplySetup’s premises are owned by the company or an exclusive partner for that reason, and its ₹799 a month GST Registration package (billed annually, 18% GST extra) is the document kit plus filing support. The ₹399 Business Address plan is mail and signage only and will not clear this tab.

Aadhaar authentication and the GSK biometric visit

On the Aadhaar Authentication tab you say yes or no for each promoter and for the authorised signatory. Yes is almost always right.

If you opt in and it succeeds: an authentication link goes to the Aadhaar-linked mobile and email of each selected person, who enters the Aadhaar number and confirms an OTP. Once everyone is authenticated, Rule 9 gives the officer 7 working days to act. If you opt out, or authentication fails: the application takes the physical verification route, the officer has 30 days, and a visit to your premises is likely.

If you are routed to biometric authentication: since 2024-25 many applicants — selection is risk-based and not published — are sent for biometric-based Aadhaar authentication and document verification at a GST Suvidha Kendra. Instead of an OTP link you get a link to book an appointment at a designated centre. Carry the confirmation, the ARN, Aadhaar and PAN in original and the original address documents. Fingerprints and a photograph are captured and the originals checked against your uploads. The application moves only once every listed person has attended.

Submitting: DSC or EVC, and the ARN

Rule 26 decides how you sign. Companies and LLPs must use a Digital Signature Certificate — a Class 3 certificate issued to the authorised signatory as an individual, on a USB token, with the emSigner utility running. Everyone else may use EVC, an OTP to the signatory’s Aadhaar-linked mobile, or e-signature.

Two warnings: a DSC belongs to a person, not the company, so the PAN inside it must match the signatory registered on the portal; and emSigner is fussy, failing at the last click on locked-down corporate laptops. Test it a day before you submit.

On successful submission the portal generates an Application Reference Number (ARN), sent by email and SMS. That is your proof of filing and the number you quote in every follow-up. Track it under Services → Track Application Status: statuses run Pending for Processing, Pending for Clarification (a REG-03 has been issued), Clarification Filed, Approved or Rejected.

What the officer does next

Rule 9 governs what happens after the ARN.

1. Examination. The proper officer examines the application and documents, and grants registration if they are in order.
2. The two windows. With Aadhaar authentication completed, the officer must act within 7 working days. Without it, or where physical verification is considered necessary, the period is 30 days, with the Rule 25 verification report and photographs filed in FORM GST REG-30.
3. The query: FORM GST REG-03. Anything deficient draws a notice seeking clarification or documents, by email and on the portal.
4. The reply: FORM GST REG-04. You must reply within 7 working days. Treat it as an emergency, not a letter: answer exactly what was asked, in the format asked, well before the deadline. There is no second reply.
5. Approval or rejection. Satisfied, the officer grants registration. Not satisfied — or no reply in time — and it is rejected in FORM GST REG-05, with reasons recorded.
6. The certificate: FORM GST REG-06. Generated with your GSTIN, downloaded from Services → User Services → View / Download Certificates. Nothing is posted.

Your GSTIN is readable: digits 1–2 the state code, 3–12 your PAN, 13 the entity number for that PAN in that state (1–9 then A–Z), 14 the letter Z by default, 15 a checksum. Karnataka begins 29, Delhi 07.

How long it really takes

Rule 9 sets the outer limits; these are the realistic ranges from ARN to GSTIN.

Before the ARN, allow one to three working days for a virtual office document kit and a day or two for a DSC. From a standing start, budget two to four weeks in all.

Your first 30 days with a GSTIN

The certificate starts the obligations. Six things need doing quickly.

Two deserve a sentence more. QRMP lets a taxpayer with turnover up to ₹5 crore file both returns quarterly while paying tax monthly, using the Invoice Furnishing Facility for B2B invoices in the first two months so customers see their credit. And the invoice series is unique per GSTIN: two registrations, two series.

Rule 10A means you need not wait for a bank account, and banks want the GST certificate as a business-existence proof anyway, so the order is GSTIN first, current account second — the current account documents guide lists what each entity type is asked for.

The ten mistakes that delay approval

1. Legal name different from the PAN database. Part A fails at once; the fix is at the income-tax end.
2. Address mismatch across form, agreement, NOC and bill. The commonest cause of REG-03.
3. Wrong nature of possession. Consent premises filed as “rented” sends the officer looking for a document that does not exist.
4. Stale or wrong-unit utility bill. Use a recent one for the exact unit, in the owner’s name.
5. Aadhaar authentication skipped. It turns a seven-day file into a thirty-day one with a site visit.
6. Oversized uploads. Compress before you start, not mid-form.
7. Contact details nobody monitors. The REG-03 goes there, and the clock runs unread.
8. Mismatched authorisation. A resolution naming someone other than the registered signatory stops the file.
9. DSC problems on submission day. Expired certificate, wrong PAN inside it, emSigner blocked by IT policy.
10. Nothing at the premises when the officer arrives. No board, no staff, a locked door — then Rule 21 cancellation.

Effective date and back-dating

Submit the application within 30 days of the date you became liable to register and the registration is effective from that date. Submit it later and it takes effect only from the date of grant.

The practical difference is a gap. Say liability arose on 5 June and you apply on 20 September: June to September sits outside the registration, so you cannot invoice tax for it and your customers cannot take credit, yet the tax is still recoverable with interest under Section 50 plus the Section 122 penalty. Backdating is not a favour the officer can grant — the rule leaves no discretion.

So the date you enter on the Business Details tab is not a formality. Use the real one: the day turnover crossed the threshold, the day you first made an inter-state supply of goods, the day you signed up as a marketplace seller. Voluntary registration is different — register before any liability arises and it runs from the date of grant, with the same filing obligations from that day.

Doing it with SimplySetup, or doing it alone

The application is free and you can file it yourself. What you cannot do yourself is manufacture an address you do not have — and that is what most first-time applicants lack.

If you own or rent commercial premises in the state and have a clean utility bill, file it alone: keep the uploads consistent, do the Aadhaar authentication, and be ready to answer a REG-03 inside seven working days. A consultant’s fee — a few hundred to a few thousand rupees — buys form-filling, not a faster officer.

If you have no premises in the state, or your landlord will not sign an NOC, the address is the task. SimplySetup’s GST Registration package is a real commercial address with the agreement, owner NOC and utility bill in one kit, your name board at the entrance, staff to receive departmental post and the verifying officer, and support until the GSTIN issues. It does not remove your obligations: returns, invoice series and the Rule 18 display stay yours. Addresses are listed city by city, and the state table gives the GST code for each.

One caution either way: a virtual office is not a way to appear present in a state where you do no business, and used that way it invites Rule 21 cancellation. It is a documented, verifiable place of business where you genuinely supply, store or serve.

What to do next

Work out which door you are coming through — the Section 22 threshold or the Section 24 list — and write down the date your liability arose, because the 30-day window in Rule 10 is the only deadline here you cannot fix afterwards. Gather the checklist in full before you open the portal, and make the address documents agree to the letter. Opt in to Aadhaar authentication, watch the registered email for the seven working days after your ARN, and download the REG-06 the day it issues. If the address is the piece you are missing, tell us the state and what you supply and we will send back the exact document list and a fixed price.