GST registration is the process through which a business or other taxable person gets a GSTIN and becomes formally recognized under the GST law. It matters because registration affects whether the person can lawfully collect GST, issue tax invoices as a registered supplier, claim eligible input tax credit, and comply with return, invoicing, and record-keeping requirements.
For many businesses, the first question is not how to register but whether registration is required at all. Under the CGST Act, that answer can arise in three different ways: threshold-based liability, compulsory registration in specified cases, or voluntary registration.
When GST registration becomes necessary
| Route | What it means | Why it matters |
|---|---|---|
| Threshold-based registration | Section 22 links liability to aggregate turnover in a financial year. | The threshold is not one universal number for every business model. |
| Compulsory registration | Section 24 requires registration for specified categories even if turnover is low. | Check the category together with any applicable registration exemption. |
| Voluntary registration | Section 25 allows a person who is not otherwise liable to register voluntarily. | Useful where customers expect a GSTIN or input tax credit flow matters commercially. |
1. Threshold-based liability
Section 22 of the CGST Act sets the basic turnover trigger. For service suppliers, the usual threshold is ₹20 lakh; it is ₹10 lakh in Manipur, Mizoram, Nagaland and Tripura. The same section also allows the Government, on notification and subject to conditions, to increase the threshold to up to Rs. 40 lakh for persons engaged exclusively in the supply of goods.
The important professional point is that Rs. 40 lakh is not a default threshold for every business. It is a conditional, notification-based position for eligible goods suppliers. A service provider should not assume that the same number applies. A mixed supplier should also test the notification conditions before relying on it. For goods, Notification 10/2019-Central Tax excludes specified States/UTs, specified products and compulsory-registration cases. Check the actual State and product against the ICAI registration handbook, threshold discussion and State table.
Compute turnover across the PAN, before testing each State
Aggregate turnover includes taxable supplies, exempt supplies, exports and inter-State supplies under the same PAN across India. It excludes GST/cess and inward supplies taxed under reverse charge. See section 2(6), reproduced in ICAI’s April 2026 bare law.
Hypothetical working: A consulting firm has actual taxable establishments in Delhi and Haryana under one PAN. During the financial year it makes the following supplies, with no other registration exemption:
| Component | Amount included |
|---|---|
| Taxable consulting supplies from Delhi | ₹15,00,000 |
| Taxable consulting supplies from Haryana | ₹6,00,000 |
| Exempt bank-deposit interest | ₹3,00,000 |
| Aggregate turnover for the PAN | ₹15,00,000 + ₹6,00,000 + ₹3,00,000 = ₹24,00,000 |
The ₹24 lakh total exceeds the ₹20 lakh threshold. On these facts, registrations are required in both States; testing ₹15 lakh and ₹6 lakh independently would give the wrong answer. The ₹40 lakh goods exemption does not apply to this consulting business. Keep a dated cumulative turnover working so that the day liability arises can be identified.
2. Compulsory registration can override thresholds
Section 24 covers cases where registration may be required even without crossing the section 22 threshold. In practical work, the categories most often checked are:
- persons making inter-State taxable supplies, subject to notified exemptions;
- casual taxable persons;
- non-resident taxable persons;
- persons required to pay tax under reverse charge;
- persons required to deduct tax at source under section 51 or collect tax at source under section 52;
- input service distributors;
- electronic commerce operators and certain persons supplying through them; and
- specified cross-border digital supply situations such as OIDAR-related registration.
For example, Notification 10/2017-Integrated Tax, as amended, exempts inter-State taxable service suppliers whose aggregate turnover does not exceed the applicable ₹20 lakh/₹10 lakh limit. An out-of-State customer therefore does not automatically require every small service provider to register. See the handbook’s notified exemptions; e-commerce and other categories also require their own conditions to be checked.
Also test section 23: a person dealing exclusively in wholly exempt or non-taxable supplies, and an agriculturist to the extent of produce from cultivation of land, is outside registration liability on that basis. See sections 22–25.
Example with assumptions: Assume a business plans to operate a temporary sales counter at an exhibition for a limited period in another State as a casual taxable person. In that case, the threshold is not the main issue; registration planning must be handled before commencement, and the special procedural rules for that category become relevant.
3. Voluntary registration
Section 25(3) permits voluntary registration even where section 22 or section 24 does not require it. This can make commercial sense when major customers prefer dealing with registered vendors, when the business wants a regular GST compliance profile, or when eligible input tax credit recovery matters to margins.
Voluntary registration is not a light label. Once granted, the person is generally treated like any other registered person for compliance purposes.
How GST registration works in practice
GST registration is State or Union territory specific. Section 25 provides that a person liable under section 22 or section 24 must apply in every State or Union territory where that liability arises. The same section also provides for a single registration in a State or Union territory, while allowing separate registrations for multiple places of business in that State or Union territory subject to conditions. The optional Rule 14A route discussed below has its own restriction on multiple registrations.
This state-wise structure explains why one legal entity can have multiple GSTINs across India.
Example with assumptions: Assume a private limited company has taxable operations in Maharashtra and Karnataka. Even with one PAN, it does not receive one all-India GST registration. It generally needs a separate registration for each State where liability arises.
Time limit to apply
Section 25 states that a person who becomes liable under section 22 or section 24 must apply within 30 days from the date on which the person becomes liable to registration. For a casual taxable person or a non-resident taxable person, the application must be made at least 5 days prior to the commencement of business.
That timing matters beyond formal compliance. Section 18 ties input tax credit in certain situations to timely registration, so a delayed application can have downstream credit consequences.
Prepare the identity and premises file
For an ordinary domestic applicant, prepare PAN and matching legal name, constitution documents, promoter/partner/director details and photographs as applicable, signatory authorization, and evidence for the principal and additional business premises. Keep email and mobile access available for verification. Prepare bank details too, but their separate post-registration deadline is explained below.
Use the current document guidance: CBIC Instruction 03/2025-GST, dated 17 April 2025, superseded the 2023 processing instruction. Its premises requirements include:
| Possession | Evidence to prepare |
|---|---|
| Owned | One acceptable ownership proof, such as a property-tax receipt, municipal khata, electricity bill or qualifying similar document. |
| Rented | Valid lease/rent agreement and ownership proof. With an unregistered agreement, include the lessor’s identity proof; a registered agreement ordinarily does not require that additional identity proof. |
| Used with an owner’s consent | Consent letter, consenter’s identity proof and evidence of the consenter’s ownership. |
These are common cases. Shared premises, rent without a written agreement and SEZ premises have further instructions. Consult paragraph 6 of the original CBIC instruction for the evidence matching your circumstances. This is not a promise that no clarification can ever be sought.
Submit REG-01 and keep the acknowledgement
Under Rule 8, the standard application route begins with FORM GST REG-01 on the GST portal. Part A captures PAN, State or Union territory and contact details. Validation generates a Temporary Reference Number (TRN) for completing Part B.
Part B records the business profile, premises, promoters or partners and authorized signatory. Upload the supporting documents, check the declaration and submit using the permitted electronic verification/signature method. Complete the authentication and document-verification steps communicated for the application.
A TRN only identifies the application in progress. Save the acknowledgement and Application Reference Number (ARN), monitor application status and retain every notice and reply. Neither a TRN nor an ARN is the registration certificate.
Aadhaar verification: a September 2026 court direction
Current development: In its interim order dated 8 September 2026, the Delhi High Court directed authorities across the country not to grant GST registration without biometric Aadhaar authentication. It allowed authorities to raise practical implementation difficulties and listed further consideration for 22 September 2026. Read paragraphs 8–10 of the official court order.
This is an interim judicial direction, not a permanent rewriting of the registration rules. Prepare for biometric verification and check the portal’s instructions and any subsequent order before filing. Do not rely on an older guide’s suggestion that declining Aadhaar merely means a longer processing time.
Which processing route applies?
Under the ordinary Rule 9 route, an application and documents found in order are generally approved within 7 working days. The rule also sets a 30-day process for specified verification cases. These periods are not a guarantee that an incomplete or unauthenticated application will receive approval; read them with the court development above.
If clarification is sought in REG-03, reply in REG-04 within 7 working days of receiving the notice. If the reply is satisfactory, Rule 9 provides a further 7-working-day approval period from receipt of that reply. Rejection is communicated in REG-05. See Rule 9.
Rules 9A and 14A: electronic registration
Notification 18/2025-Central Tax introduced these routes from 1 November 2025:
- Rule 9A: the portal identifies eligible applications using data analysis and risk parameters; electronic registration is prescribed within 3 working days.
- Rule 14A: an optional route where monthly output tax liability on supplies to registered persons does not exceed ₹2.5 lakh, counting central, State/UT and integrated tax plus compensation cess. This is a tax-liability test, not a turnover exemption.
Rule 14A provides electronic grant within 3 working days on successful Aadhaar authentication, subject to its conditions; read its statutory authentication provisions alongside the interim order above. Only one Rule 14A registration per PAN in the same State/UT is allowed.
Monitor the limit after registration. Withdrawal uses REG-32 and has return-filing and other conditions. Permission to report liability above the limit starts from the month following the withdrawal order. Read the complete rule before choosing the option.
What happens after registration is granted
Once the registration certificate in FORM GST REG-06 is made available and the GSTIN is assigned, the work is not finished.
- For registrations covered by Rule 10A, furnish bank details in the registered person’s name and linked to the PAN within 30 days of grant, or before GSTR-1/IFF, whichever comes first. Registrations granted under Rules 12 and 16 are excepted. See Rule 10A.
- The registered person must maintain records at the principal place of business as required by section 35 and the rules.
- Changes in core registration particulars such as legal name, principal place of business, or key constitution details require amendment procedures.
This post-registration step is often missed in smaller businesses. The consequence is practical as well as procedural, because the rules now link bank-detail compliance with later return functionality.
Common professional mistakes at the registration stage
- Using an address proof that does not clearly support the exact principal place of business claimed.
- Assuming the Rs. 40 lakh position applies to every small business without checking whether the business is exclusively supplying goods and whether the notification conditions fit.
- Treating one PAN as enough for one all-India GSTIN.
- Ignoring compulsory-registration categories because turnover is still low.
- Delaying bank account updation after grant of GSTIN.
- Submitting mismatched promoter, signatory, PAN, Aadhaar, or contact details that trigger officer queries.
A short decision framework
If you need to explain GST registration basics to a client or finance team, this sequence usually resolves the issue quickly:
- Identify the State or Union territory from which the supply is made.
- Test whether section 24 creates compulsory registration regardless of turnover.
- If not, compute aggregate turnover and test the section 22 threshold actually applicable to that business model.
- Check whether the person wants voluntary registration for commercial reasons.
- Prepare a document file that cleanly supports constitution, premises, signatory authority, and bank details.
- Complete required authentication, track notices and verify the certificate and bank-detail compliance after grant.
Keep the turnover calculation, reason for registration, submitted documents, acknowledgement, notices and replies together with the certificate. That file should explain both why registration was required and how the submitted particulars were supported.
