Can I get one GSTIN for my business across all of India?

No. A GSTIN starts with a 2-digit state code, and registration under Section 25 of the CGST Act is state by state. Multi-State Registration changes how you apply, not how many GSTINs you end up with. A business registered in three states still holds three GSTINs, all built on the same PAN.

Do I need to register in a state just because my customers are there?

Not for that reason alone. You register in a state from which you make taxable supplies, which usually means a place of business there, such as an office, a warehouse or a branch. Selling to customers in another state is an inter-state supply and is handled with IGST from your own state's registration. Registering in the customer's state is a separate question that depends on your own place of business and supplies.

What is a Master TRN, and how long is a TRN valid?

As CAs describe the portal screens, the Master TRN is the Temporary Reference Number tied to the common application that the state-wise TRNs hang off. An ordinary TRN is valid for 15 days, so finish and submit each state's Part B within that window. GSTN has not published a note explaining the Master TRN, so check the portal's own on-screen guidance.

Will I file one GSTR-3B for all my states?

No. Returns, tax payment and e-way bills are all per GSTIN. If you hold GSTINs in Karnataka and Maharashtra, you file GSTR-1 and GSTR-3B separately for each one, and input tax credit does not move between them without an ISD or a proper invoice.

GST Multi-State Registration: Master TRN Is Not One GSTIN

If you run a business that is about to open a branch or warehouse in a second or third state, you may have seen screenshots of a new Multi-State Registration option on the GST portal and wondered whether it finally gives you one GSTIN for all of India. It doesn't. As described by CAs who have tried it, one common application is shared across states and each state still issues its own GSTIN. This post covers what the option appears to do, what it does not change, and what to get right before you submit.

Status as of 1 October 2026. The option was reported on the GST portal on 1 October 2026, mainly through CAs posting screenshots on X. GSTN had not published an official note on who is eligible, what documents are needed or how the screens work at the time of writing. The portal steps below are therefore as reported and may differ from what you see. What does not depend on the portal is the law: Section 25 of the CGST Act, 2017 requires registration in each state or union territory from which you make taxable supplies.

What Multi-State Registration appears to do

The normal route is one application per state. You start Part A of Form GST REG-01 with your PAN, mobile number, email and the state, get a Temporary Reference Number (TRN), then fill Part B for that state. If you want to register in four states, that is four separate applications, with the same PAN, constitution, promoter and bank details typed in four times.

As reported, the new option runs a common profile once and spreads it across states:

You begin one application and receive a Master TRN.
After you submit, the portal generates a state-wise TRN for each state you picked.
The details that are the same everywhere (PAN, constitution, promoter or partner details) are filled once and copied into each state's application.
Each state still needs its own place of business details, and goes through its own officer and its own approval.

That is a shared application flow. It is a convenience for repeat data entry, not a change to the registration itself.

What it is not: one GSTIN for all India

A GSTIN is 15 characters, and the first two are the state code. Maharashtra is 27, Karnataka is 29, Delhi is 07. The next ten are your PAN, which is the same in every state, and the rest is a registration number for that PAN in that state, a fixed Z and a checksum. One PAN with registrations in Maharashtra and Karnataka gives you 27… and 29… GSTINs that share the middle.

Nothing in the reported feature changes that. GST is administered by the central and state tax authorities together, and registration is tied to a state. Treat any claim that Multi-State Registration gives you "one GSTIN for all India" as wrong.

Who it helps, and who it doesn't

It helps a business that is setting up in several states in one go, for example a manufacturer opening warehouses in three states before a festive season, or an e-commerce seller adding fulfilment centres. You enter the shared details once.

It does not help with:

A second place of business in the same state. That is handled inside your existing registration as an additional place of business, or through a separate registration for that place under Section 25(2) if you choose it. It is not a multi-state case.
Registering in a state where you have no place of business. Having customers in a state does not by itself create the need to register there. See the second FAQ below.
Getting out of any state's verification. Each application is still reviewed in its state, and the biometric and Aadhaar authentication rules in our registration post still apply to each one.

What to check before you submit

Because the common fields are copied into every state's application, a mistake is copied too.

PAN and legal name. They must match exactly what the Income Tax database shows. A mismatch would be carried into every state.
Constitution and promoter or partner details. Names, Aadhaar-linked details and the authorised signatory are shared. Confirm them before you submit.
Mobile number and email. OTPs and officer queries are sent here, so use contacts you will actually monitor.
Per-state details. Principal place of business, proof of address for each premises (rent agreement and rent receipt, or a consent letter if the owner lets you use it), and HSN or SAC codes for each state.
Your TRNs. An ordinary TRN is valid for 15 days. Do not leave any state's Part B pending.

If a common detail turns out to be wrong, you will likely have to fix it state by state through the usual amendment route, so it is cheaper to get it right the first time.

After the ARN: every state works on its own

Once you submit, each state's application moves through its own review, and on approval you hold a GSTIN per state. From then on, state by state:

Returns. GSTR-1 and GSTR-3B are filed per GSTIN, with their own due dates. The GST return due date calendar lets you pick a filing type and your state, and QRMP due dates depend on the state of registration.
Invoices. Each invoice shows the GSTIN of the state it is issued from.
E-way bills. Generated against the GSTIN of the supplying state.
Input tax credit. It stays with the GSTIN that received the invoice.

When your GSTINs arrive, run each one through the GSTIN validator. It decodes the state code and PAN and recomputes the checksum, so a wrong state or a typo shows up before the number goes on an invoice. It only checks the format. To confirm that a GSTIN is active, use Search Taxpayer on the GST portal.

The bottom line

Multi-State Registration, as reported on 1 October 2026, is a shared application: one Master TRN, state-wise TRNs behind it, and one GSTIN per state at the end. It saves repeat typing when you are opening in several states at once, and it makes any mistake in the common fields multiply. It does not create a national GSTIN, does not remove the need for a place of business in each state, and does not change returns, which remain per GSTIN. Until GSTN issues an advisory on eligibility and documents, rely on the portal's own on-screen instructions for the steps.

Sources

This post reflects portal behaviour as reported by practitioners on 1 October 2026 and the state-wise registration requirement of Section 25 of the CGST Act, 2017. GSTN had not published an official note on the feature at the time of writing. Re-check the GST portal and any GSTN advisory before you rely on the steps above.