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GST · Beginner · 7 min read

What is GST? A Beginner's Guide

GST is the single tax that replaced 17 separate indirect taxes in India. Here's everything a business owner needs to know in plain language — what GST is, who pays it, and how the rates work.

What is GST?

GST stands for Goods and Services Tax. It is a single, destination-based indirect tax on the supply of goods and services across India. GST came into force on 1 July 2017 and replaced 17 separate central and state taxes — excise, service tax, VAT, octroi, entry tax and others — with one unified system.

GST in one sentence A tax you collect from customers, pay to the government, and offset against the tax you paid on purchases — so only the value you add is effectively taxed.

Why GST Replaced the Old System

Before 2017, the same product would be taxed multiple times as it moved through the supply chain — and tax paid at one stage could rarely be credited against tax due at the next. This cascading effect made Indian goods more expensive and the tax system extremely complex. GST eliminates cascading through a continuous input-tax-credit chain from the first supplier all the way to the final consumer.

CGST, SGST & IGST

India is a federal country, so GST revenue is shared between Centre and States. Every GST transaction is split into components based on where supplier and buyer are located:

TaxWhen it appliesWho collects
CGSTIntra-state supply (same state)Central Government
SGST/UTGSTIntra-state supplyState or UT Government
IGSTInter-state supply, importsCentral Govt (split later)

Example: A Mumbai trader sells ₹10,000 worth of goods at 18% GST.

  • To a Pune customer (same state) → CGST 9% (₹900) + SGST 9% (₹900) = ₹1,800
  • To a Bangalore customer (different state) → IGST 18% (₹1,800)

GST Tax Slabs

SlabExamples
0% (Nil)Fresh fruits, vegetables, milk, unbranded atta, books
5%Sugar, tea, packaged food, life-saving drugs, footwear under ₹1,000
12%Butter, ghee, mobile phones, processed food, computers
18%Most services, soaps, hair oil, capital goods, IT services
28%Luxury items, motor cars, ACs, tobacco, aerated drinks
0.25% / 3%Rough diamonds, gold and silver jewellery

Who Has to Register?

  • ₹40 lakh turnover for goods-only businesses (₹20 lakh in special-category states)
  • ₹20 lakh turnover for service businesses (₹10 lakh in special-category states)
  • Mandatory regardless of turnover for inter-state sales, e-commerce sellers, reverse-charge cases and casual taxable persons

How GST Helps Businesses

  • One tax across India — no more state-level check-posts
  • Input tax credit recovers GST paid on purchases
  • Faster inter-state logistics (no entry tax, no octroi)
  • All compliance is online at gst.gov.in
In iAccounting

iAccounting auto-applies the correct CGST/SGST/IGST split on every invoice based on the customer's GSTIN. HSN codes and tax rates are pre-configured — you just bill, the calculation happens automatically.

See GST automation →

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