GST Registration in India: A Complete 2026 Guide for New Businesses

If you’re starting or growing a business in Guwahati or anywhere else in India, GST registration is usually the first compliance step you’ll run into — and one of the easiest to get wrong. Miss the threshold date by a few weeks, file with the wrong documents, or pick the wrong registration type, and you’re looking at penalties, blocked input tax credit, or a rejected application that sends you back to square one. This guide walks through who actually needs to register, what the process looks like in 2026, and the mistakes we see most often at TaxSure.

Do you actually need GST registration?

GST registration becomes mandatory once your aggregate turnover crosses a threshold that depends on what you sell and where you’re based:

• Suppliers of goods: ₹40 lakh in most states; several special-category states (including Assam, which raised its own limit) also apply the ₹40 lakh threshold for goods.
• Suppliers of services: ₹20 lakh in most states, with a lower threshold in a handful of special-category states.
• Certain businesses regardless of turnover: e-commerce sellers, businesses making inter-state taxable supplies, casual taxable persons, and anyone required to pay tax under reverse charge must register irrespective of turnover.

Because the special-category rules vary by state and by whether you sell goods or services, the safest move if you’re near the threshold is to get your exact number confirmed before you assume you’re exempt — a wrongly-skipped registration attracts penalties even if it wasn’t deliberate. Many businesses also register voluntarily below the threshold, mainly to claim input tax credit and to look more credible to larger B2B customers who prefer working with GST-registered vendors.

Documents you’ll need

Keep these ready before you start the application — most delays happen because a document is missing or doesn’t match across records:

• PAN of the business or proprietor
• Aadhaar of the proprietor/partners/directors
• Proof of business address (electricity bill, rent agreement with NOC, or property tax receipt)
• Bank account proof — a cancelled cheque, bank statement, or the first page of a passbook
• Passport-size photographs of proprietors, partners, or directors
• For companies and LLPs: Certificate of Incorporation, MOA/AOA or LLP agreement, and board resolution authorising the signatory
• Digital Signature Certificate (mandatory for companies and LLPs)

The registration process, step by step

1. Part A of Form GST REG-01: Submit PAN, mobile number, and email on the GST portal. You’ll receive an OTP-verified Temporary Reference Number (TRN).
2. Part B of Form GST REG-01: Using the TRN, fill in business details, promoter/partner information, principal place of business, bank details, and upload the supporting documents.
3. Aadhaar authentication: Most applicants now complete e-KYC via Aadhaar OTP, which speeds up approval considerably.
4. Verification: A GST officer reviews the application. If everything is in order, registration is typically granted within 7 working days; if Aadhaar authentication isn’t opted for or the officer flags a discrepancy, it can take longer and may involve a site visit or a notice in Form GST REG-03, which you must respond to within 7 working days.
5. GSTIN issued: On approval, you receive your 15-digit GSTIN and can download the registration certificate (Form GST REG-06) from the portal.

Common mistakes that slow things down

• Address proof mismatch: The name on the electricity bill or rent agreement doesn’t match the applicant’s name, or the NOC from the property owner is missing.
• Wrong business constitution selected: Choosing “Proprietorship” instead of “Partnership,” or the wrong entity type, forces a fresh application later.
• Incorrect HSN/SAC codes: Picking codes that don’t match your actual goods or services creates return-filing headaches for years afterward.
• Ignoring a GST REG-03 notice: Missing the 7-working-day reply window means the application is rejected outright and you have to start over.
• Registering late: Liability to register starts from the date you cross the threshold, not the date you apply — late registration can mean paying tax, interest, and penalty on past supplies without having collected GST from customers to cover it.

After registration: what changes immediately

Once registered, you’re expected to issue GST-compliant invoices, file periodic returns (GSTR-1 and GSTR-3B at minimum, on a monthly or quarterly basis depending on your turnover and the QRMP scheme), and reconcile input tax credit against what your suppliers report. None of this is difficult in isolation, but missing a single monthly deadline early on can snowball into interest, late fees, and a messy annual return. This is usually the point where businesses either build a disciplined compliance calendar in-house or hand the recurring filings to someone who already has one.

How TaxSure helps

We handle GST registration end-to-end for businesses across Assam and the rest of India — document review, application filing, responding to department queries, and setting you up with a return-filing calendar so nothing slips through afterward. If you’re not sure whether you’ve already crossed the threshold, or which category your business falls under, that’s exactly the kind of question worth a quick call before you file anything.

Book a free consultation and we’ll walk you through exactly what your business needs.