GST and why registration matters for any business
GST — Goods and Services Tax — is India's unified indirect tax. If you run a business that sells goods or services, GST registration is often required. Even when it is not mandatory, having a GSTIN opens doors: input tax credit, B2B customers who need your GSTIN on invoices, and readiness for e-invoicing.
This article covers what GST is, why registration matters, and the practical steps to register on the official portal.
What GST is
Before July 2017, businesses in India dealt with a stack of indirect taxes — excise, VAT, service tax, and more. Each state had its own rules. Goods moving across state borders faced tax-on-tax ("cascading").
GST replaced most of these with one framework. It is collected at each stage of the supply chain, but you only pay tax on the value you add — not on tax already paid.
The three types of GST
| Type | What it means |
|---|---|
| CGST | Central GST — goes to the central government |
| SGST | State GST — goes to the state where the sale happens |
| IGST | Integrated GST — applies to interstate or import transactions; split later between centre and destination state |
When you sell within your state, CGST + SGST apply (split equally). When you sell to another state, IGST applies instead.
Why GST registration matters
Registration gives you a GSTIN — a 15-digit identifier unique to your business in a state. Here is why it matters:
1. Legal requirement above threshold
Businesses with aggregate turnover above the notified threshold must register. Thresholds differ by state and business type. Check the current threshold on the GST Portal — this article does not quote amounts because they can change.
2. Input tax credit (ITC)
Registered businesses can claim credit for GST paid on purchases. If you buy raw materials for ₹100 + ₹18 GST, and sell the finished product for ₹150 + ₹27 GST, you remit only ₹9 (₹27 minus ₹18 credit). Without registration, you pay the full ₹18 and cannot recover it.
3. B2B customers need your GSTIN
Many corporate buyers and government departments only accept invoices with a valid GSTIN. No GSTIN means you lose those orders or the buyer cannot claim their own ITC.
4. E-invoicing and e-way bills
Certain turnover thresholds require e-invoicing (IRN) and e-way bills for moving goods. You need a GSTIN to generate these on the government portals.
5. Credibility
A GSTIN on your invoice signals that you are a registered, compliant business. It builds trust with customers, vendors, and banks.
6. Avoiding penalties
Operating without registration when required invites penalties, interest, and possible prosecution. The cost of compliance is far lower.
Who typically needs to register
GST registration is mandatory in several situations. These are the common triggers — verify your specific case on the official portal or with a tax professional:
| Situation | Likely mandatory? |
|---|---|
| Turnover above the notified threshold | Yes |
| Any interstate supply of goods (regardless of turnover) | Yes |
| E-commerce sellers or operators | Yes |
| Casual taxable persons (temporary business in a state) | Yes |
| Non-resident taxable persons | Yes |
| Agents or input service distributors | Yes |
| Reverse charge liability | Yes |
| TDS/TCS deductors/collectors under GST | Yes |
Even if you are below threshold, voluntary registration is allowed. Many small businesses register early to claim ITC and work with B2B customers.
Basic steps to register on the GST portal
Registration happens online at reg.gst.gov.in/registration. The process has two parts: Part A (get a Temporary Reference Number) and Part B (complete the application).
Step 1 — Visit the portal and start Part A
Go to the GST registration portal. Select "New Registration." Choose whether you are a taxpayer, TDS deductor, etc.
Step 2 — Enter basic details
Provide your state, district, legal name, PAN, email, and mobile number. The portal sends OTPs to both email and mobile for verification.
Step 3 — Receive TRN
After OTP verification, you receive a Temporary Reference Number (TRN). Save this — you need it to continue Part B.
Step 4 — Log in with TRN and complete Part B
Use the TRN to log back in. Part B asks for:
- Business details (trade name, constitution, date of commencement)
- Promoter / partner / proprietor details
- Principal place of business and additional places
- Bank account details
- Goods and services you deal in (HSN/SAC codes)
- Authorised signatory details
Step 5 — Upload documents
Attach scanned copies of required documents (see checklist below). File size limits apply — check the portal's instructions.
Step 6 — Verify and submit
Review all sections. Submit using Aadhaar-based e-sign, DSC (digital signature certificate), or EVC (electronic verification code) depending on your constitution.
Step 7 — Receive ARN
After submission, you get an Application Reference Number (ARN). The tax officer reviews your application. You can track status using the ARN.
Step 8 — GSTIN issued
If approved, your GSTIN and registration certificate are available for download on the portal. If the officer raises queries, respond within the time limit shown.
Documents commonly needed
The exact list depends on your business constitution (proprietor, partnership, company, etc.). Keep these ready:
| Document | Notes |
|---|---|
| PAN | Of the business entity (or proprietor for sole proprietorship) |
| Aadhaar | Of the proprietor / partners / directors / authorised signatory |
| Proof of business address | Electricity bill, rent agreement, property tax receipt, NOC from owner |
| Bank account proof | Cancelled cheque, bank statement, or passbook first page showing account number and IFSC |
| Photographs | Passport-size photos of promoters / partners / directors |
| Constitution documents | Partnership deed, incorporation certificate, board resolution, etc. as applicable |
| Authorisation letter | If someone other than the primary person is signing |
Photo and file-size specifications are listed on the portal. Prepare clear, legible scans before starting Part B.
After registration
Once you have your GSTIN:
- Print it on every invoice — it is a legal requirement for tax invoices.
- File returns on time — monthly or quarterly depending on your scheme. Late filing attracts interest and late fees.
- Maintain records — invoices, purchase registers, stock records — as required under GST law.
- Update details — if your address, bank account, or partners change, amend your registration on the portal.
Return due dates and forms are published on the GST Portal. Set calendar reminders.
Official links
These are the government portals for GST registration and information:
| Portal | URL |
|---|---|
| GST Portal (main) | www.gst.gov.in |
| New Registration | reg.gst.gov.in/registration |
| GST Services / Login | services.gst.gov.in |
| CBIC GST | cbic-gst.gov.in |
The portal also has user manuals, FAQs, and video tutorials under the "Help" section. When in doubt, refer to official notifications — rules and thresholds can change.
Short summary
- GST is India's unified indirect tax — CGST, SGST, and IGST depending on the transaction.
- Registration is mandatory above certain thresholds and for specific categories (interstate supply, e-commerce, etc.).
- Benefits include input tax credit, B2B eligibility, e-invoicing readiness, and credibility.
- Process is online: Part A for TRN, Part B for full application, then verification and GSTIN issuance.
- Documents vary by constitution — PAN, Aadhaar, address proof, bank proof, photos, and authorisation.
Keep your GSTIN on invoices, file returns on time, and check the official portal for current rules. Registration is the starting point — compliance is what keeps it useful.
If you run multiple outlets, each state you operate in may need its own GSTIN. Oflync Billing Desk helps you manage multi-outlet invoicing with the right GSTIN on each bill.