India’s Goods and Services Tax (GST) system, implemented on July 1, 2017, unified the country’s indirect tax framework by replacing 17 central and state taxes with a single, destination-based tax on supply. This guide covers the core compliance requirements, including registration, return filing, Input Tax Credit, e-invoicing, e-way bills, and recent regulatory changes. Whether you are a small business owner, a large enterprise, or a tax professional, understanding these compliance obligations is essential to avoid penalties and optimise tax benefits.
GST Framework Overview
GST is structured as a dual tax system in which both the central and state governments levy tax on the same transaction. For intra-state supplies, CGST (central) and SGST (state) are charged at equal rates. For inter-state supplies, IGST is charged at the combined rate. UTGST replaces SGST for Union Territories without a legislature.
The tax is collected at each stage of the supply chain, from raw material procurement to final sale. At every stage, businesses claim ITC on the tax paid on their purchases and pay only the net difference to the government. This mechanism eliminates the cascading tax effects that existed under the previous regime.
GST Rate Structure
| Rate | Goods Examples | Services Examples |
| 0% | Fresh produce, milk, cereals, books | Healthcare, education |
| 5% | Packaged food, economy air travel, and fertilisers | Goods transport, economy hotels |
| 12% | Processed food, clothing above Rs. 1,000 | Business class air travel, work contracts |
| 18% | Industrial machinery, electronics, capital goods | IT services, financial services, telecom |
| 28% | Luxury items, motor vehicles, tobacco | Five-star hotel rooms above Rs. 7,500 |
| 28% + Cess | Luxury cars, pan masala, and aerated beverages | Not applicable |
Registration and Compliance Requirements
Registration Thresholds
| Business Type | Threshold | Special Category States |
| Goods suppliers | Rs. 40 lakh aggregate turnover | Rs.20 lakh |
| Service providers | Rs. 20 lakh aggregate turnover | Rs.10 lakh |
| E-commerce operators | Mandatory regardless of turnover | Same |
| Inter-state suppliers | Mandatory regardless of turnover | Same |
| Casual/Non-resident taxable persons | Mandatory regardless of turnover | Same |
Return Filing Calendar
| Return | Filed By | Frequency | Due Date |
| GSTR-1 | All regular taxpayers | Monthly/Quarterly | 11th/13th of the following month |
| GSTR-3B | All regular taxpayers | Monthly/Quarterly | 20th/22nd-24th of the following month |
| GSTR-4 | Composition dealers | Annual | April 30 of the following FY |
| GSTR-6 | Input Service Distributors | Monthly | 13th of the following month |
| GSTR-8 | E-commerce operators | Monthly | 10th of the following month |
| GSTR-9 | All regular taxpayers | Annual | December 31 of the following FY |
Input Tax Credit Mechanism
ITC is the cornerstone of GST compliance. Registered businesses offset the tax paid on purchases against the tax collected on sales. To claim ITC, the buyer must hold a valid GST registration, possess a valid tax invoice, have received the goods or services, the credit must reflect in GSTR-2B (verified through IMS from October 2024), GSTR-3B must be filed within the prescribed deadline, and payment to the supplier must be made within 180 days.
Section 17(5) of the CGST Act blocks ITC on specific categories, including motor vehicles (with exceptions), food and beverages, club memberships, health and life insurance (unless mandatory), construction of immovable property, and goods lost, stolen, destroyed, or given as gifts.
E-Invoicing Requirements
E-invoicing is mandatory for businesses with an aggregate turnover exceeding Rs. 5 crore. Each B2B invoice must be registered on the Invoice Registration Portal (IRP), which assigns a unique Invoice Reference Number (IRN) and digitally signs the invoice with a QR code.
E-invoice data auto-populates into GSTR-1 and the e-way bill system, reducing manual data entry and improving accuracy. Non-compliance with e-invoicing results in the invoice being treated as invalid, and the recipient cannot claim ITC on such invoices.
E-Way Bill System
E-way bills are mandatory for transporting goods valued at more than Rs. 50,000. The bill is generated on the e-way bill portal (ewaybillgst.gov.in) with a validity of 1 day per 200 km. The system tracks goods movement and prevents tax evasion during transit.
Non-compliant taxpayers (those who have not filed GSTR-3B for two consecutive months) are blocked from generating e-way bills until their filings are regularised.
Recent Regulatory Changes
| Update | Effective Date | Impact |
| Invoice Management System (IMS) launch | October 1, 2024 | Recipients must accept/reject supplier invoices before ITC flows into GSTR-2B. |
| The ISD mechanism was made mandatory | April 1, 2025 | Common input service credits must be routed through ISD registration |
| HSN Phase III in GSTR-1 | January 2025 | Dropdown HSN selection mandatory; separate B2B/B2C tabs in Table 12 |
| GSTR-3B hard-locking announced | July 2025 (planned) | Auto-filled Table 3 values in GSTR-3B cannot be manually adjusted |
| 3-year filing restriction | July 2025 | Returns cannot be filed more than 3 years after the due date |
| ITC manual capture via IMS | October 2025 | ITC no longer auto-populates in GSTR-3B; must be captured through IMS |
Businesses must stay updated on these changes through the official GST portal advisories and CBIC notifications. Non-compliance with new requirements can result in ITC denial, penalty, and increased audit scrutiny.
Key Terms
• GST Council: The constitutional body that determines GST rates, rules, and procedures, comprising the Union Finance Minister and all state finance ministers
• Place of Supply: The legal determination of where a supply occurs, governing whether CGST/SGST or IGST applies to the transaction
• Composition Scheme: The simplified GST option for small businesses with turnover up to Rs. 1.5 crore, allowing payment at fixed rates without ITC
• Reverse Charge Mechanism: The provision shifting GST payment responsibility from the supplier to the recipient for specified categories of supplies
• Electronic Credit Ledger: The online account on the GST portal where ITC is maintained and utilised against output tax liability
Staying Compliant with GST?
Navigate GST regulations confidently with the right tools and knowledge. Use WFYI resources to manage registration, track filing deadlines, and optimise your tax compliance.
| Disclaimer: This article is for informational purposes only and does not constitute legal or tax advice. Consult a qualified tax professional for advice specific to your situation. |
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Frequently Asked Questions
Q1: What taxes did GST replace in India?
GST replaced 17 central and state taxes, including Central Excise Duty, Service Tax, VAT, CST, Entry Tax, Purchase Tax, Luxury Tax, Entertainment Tax, and Octroi, creating a unified indirect tax framework for the entire country.
Q2: Is GST registration mandatory for all businesses?
No. Registration is mandatory only when the aggregate turnover exceeds Rs. 40 lakh for goods suppliers (Rs. 20 lakh in special category states) or Rs. 20 lakh for service providers (Rs. 10 lakh in special category states). E-commerce operators and interstate suppliers must register regardless of turnover.
Q3: What is the Invoice Management System, and is it mandatory?
IMS is a GST portal dashboard launched in October 2024 for verifying supplier invoices. From October 2025, it will be effectively mandatory, as ITC will no longer auto-populate in GSTR-3B without IMS action.
Q4: How many GST rate slabs exist in India?
There are five main rate slabs: 0% (exempt), 5%, 12%, 18%, and 28%. An additional compensation cess applies to luxury and demerit goods above the 28% base rate.
Q5: What is the penalty for not filing GST returns on time?
Late filing attracts a fee of Rs. 50 per day (Rs. 20 for Nil returns), subject to a maximum cap. Additionally, interest at 18% per annum applies on the outstanding tax liability from the due date until the date of payment.
