GST Number Registration

A GST number, officially called the Goods and Services Tax Identification Number (GSTIN), is a unique 15-digit code issued to every person or business registered under GST. It identifies the taxpayer on the GST portal and must be quoted on invoices, e-way bills, and all GST returns.

Without a valid GST number, a business cannot legally collect GST from customers, cannot claim input tax credit on its purchases, and is often unable to onboard with corporate clients, marketplaces, or payment gateways that require a GSTIN for verification.

The first 2 digits of a GSTIN represent the state code as per the Indian Census, the next 10 digits are the PAN of the business or individual, and the 13th digit indicates the number of registrations the entity holds within that state on the same PAN.

The 14th digit is always "Z" by default, and the 15th digit is a checksum character used to detect errors in the number. Understanding this structure makes it easy to visually verify whether a GSTIN's state code and PAN portion look consistent with the business it claims to belong to.

You can apply for a GST number on the official GST portal by filling Form GST REG-01 in two parts — Part A for generating a Temporary Reference Number (TRN) using PAN, mobile number, and email, and Part B for submitting business details, promoter information, and supporting documents against that TRN.

The complete step-by-step walkthrough, including screenshots of each portal screen, is covered on the page for the GST registration process online.

At a minimum, you need PAN and Aadhaar of the applicant, a passport-size photograph, proof of the business's principal place of business (electricity bill, rent agreement, or property tax receipt), and bank account details in the form of a cancelled cheque or bank statement.

Companies and partnership firms need additional documents such as the incorporation certificate, partnership deed, or board resolution. The full list, sorted by business type, is available on the page covering documents required for GST registration.

If Aadhaar authentication is completed successfully and the application is free of errors, a GST number is generally issued within 3 to 7 working days. If Aadhaar authentication fails or is skipped, the officer may order physical verification of the business premises, which can extend the timeline to around 15 to 30 days.

You will receive updates on your registered email and mobile number at every stage, from ARN generation to final approval.

The government does not charge any fee on the GST portal to issue a GST number — the application itself is completely free. Costs are only incurred if you hire a tax professional or consultant to prepare documents, fill the form correctly, and follow up on queries raised by the department.

A detailed breakup of typical professional charges by business type is available on the page for GST registration fees in India.

You can verify any GST number using the "Search Taxpayer" tool on the official GST portal by simply entering the 15-digit GSTIN. The result will show the legal name, business constitution, registration status, and the date from which the registration is effective.

If the GSTIN shows as "inactive," "cancelled," or does not match the vendor's name on the invoice, it is a strong warning sign before you claim input tax credit on that bill or make payment against it.

There is no same-day or "instant" GST number for regular taxpayers, since the department verifies documents and, in many cases, completes Aadhaar authentication before granting registration. The fastest realistic timeline is around 3 working days when everything is in order and biometric or Aadhaar-based verification is completed without issues.

Casual taxable persons and non-resident taxable persons follow a different, faster process but must apply at least 5 days before commencing business and pay an advance deposit of estimated tax liability.

GSTIN and GST number refer to the exact same thing — the 15-digit Goods and Services Tax Identification Number allotted to a registered taxpayer. "GST number" is simply the commonly used, informal term, while "GSTIN" is the official abbreviation used in GST law, the GST portal, and all statutory forms.

There is no separate or additional identifier apart from the GSTIN once a business is registered under GST.

Yes. A single PAN holder can obtain multiple GST numbers — one for each state where the business has a place of operation, since GST registration is state-specific. Within the same state, a business can also register separate GST numbers for distinct business verticals, provided the conditions under the CGST Rules for multiple registrations are met.

Each such GSTIN is tracked, filed, and audited independently, even though all of them share the same underlying PAN of the taxpayer.

If the officer is not satisfied with the application or supporting documents, a Show Cause Notice is issued in Form GST REG-03, and you get an opportunity to respond with clarification or additional proof in Form GST REG-04, usually within 7 working days.

If the response is unsatisfactory or not submitted in time, the application is rejected through Form GST REG-05, after which you would need to file a fresh application correcting the issues that led to rejection, such as address mismatch or incomplete promoter details.

Yes, the GST portal allows you to search for a taxpayer's GSTIN using their legal name, trade name, or PAN through the "Search Taxpayer" option, without needing to already know the full 15-digit number. This is commonly used to verify a vendor's registration before onboarding them or processing a payment.

The search results also show the taxpayer's registration date, business type, and current GST status, helping you cross-check the details mentioned on their invoice.

No, a GST number is not uniform across states. Since the first two digits of the GSTIN represent the state code, a business operating in multiple states will hold a different 15-digit GST number in each state, even though digits 3 to 12 (the PAN) remain identical throughout.

This is why an incorporated company expanding to a new state must apply for a fresh GST registration for that state rather than simply using its existing GSTIN.

You can retrieve a lost or forgotten GST number by logging into the GST portal with your registered username, or by using the "Search Taxpayer" tool and searching with your business PAN or legal name, since the GSTIN is derived directly from the PAN.

Your GSTIN is also printed on your GST registration certificate, on past GST returns filed, and on any sales invoice you have previously issued, making it easy to cross-verify once retrieved.

Yes, a taxpayer can apply for voluntary cancellation of their GST number in Form GST REG-16 if the business is discontinued, transferred, merged, or turnover falls below the threshold and continued registration is no longer required. The department can also cancel a GSTIN on its own if returns are not filed for a prescribed continuous period.

Before cancellation is approved, the taxpayer must clear all pending liabilities and file a final return, and businesses undergoing structural changes such as those completing annual compliance for a Pvt Ltd company should factor this in during the transition.