GST Filing Complete Guide for Small Businesses 2024-25

1. What is GST?

Goods and Services Tax (GST) is a comprehensive, multi-stage, destination-based tax that is levied on every value addition in India. Introduced on 1st July 2017, GST replaced a complex system of multiple indirect taxes like VAT, Service Tax, Excise Duty, and many others.

GST has four tax slabs: 5%, 12%, 18%, and 28%, with certain essential goods taxed at 0%. Every registered business must collect GST from customers and deposit it with the government after adjusting Input Tax Credit (ITC).

2. Who Needs GST Registration?

GST registration is mandatory for the following businesses:

• Businesses with annual turnover exceeding ₹40 lakhs (goods) or ₹20 lakhs (services)
• For special category states: threshold is ₹20 lakhs (goods) or ₹10 lakhs (services)
• Businesses involved in inter-state supply of goods and services (regardless of turnover)
• E-commerce operators and sellers on platforms like Amazon, Flipkart
• Businesses liable to pay tax under reverse charge mechanism
• Casual taxable persons and non-resident taxable persons
• Businesses registered under earlier tax laws (VAT, Service Tax, etc.)

Voluntary Registration

Even if your turnover is below the threshold, you can voluntarily register for GST. This is beneficial if you want to claim Input Tax Credit or deal with GST-registered businesses.

3. Documents Required for GST Registration

Document	Purpose
PAN Card of Business/Proprietor	Primary identification
Aadhaar Card	Identity verification
Business Registration Proof	Certificate of incorporation, partnership deed, etc.
Address Proof of Business	Electricity bill, rent agreement, or NOC
Bank Account Details	Cancelled cheque or bank statement
Digital Signature Certificate	For companies and LLPs only
Passport Size Photo	Of proprietor/directors/partners

4. Types of GST Returns

Different types of businesses file different GST returns. Here are the most common ones:

• GSTR-1: Details of outward supplies (sales). Filed monthly or quarterly.
• GSTR-3B: Monthly summary return of sales, purchases, and tax payment.
• GSTR-9: Annual return for regular taxpayers. Due by 31st December.
• GSTR-9C: Reconciliation statement certified by CA. Required for turnover above ₹5 crore.
• GSTR-4: Annual return for composition scheme taxpayers.
• CMP-08: Quarterly challan for composition scheme taxpayers.

5. Step-by-Step Filing Process

Step 1: Gather Your Data

Before filing, collect all sales invoices, purchase invoices, credit/debit notes, and bank statements for the period.

Step 2: Log into GST Portal

Visit gst.gov.in and login with your GSTIN and password. Navigate to the "Returns Dashboard."

Step 3: File GSTR-1 (Sales Return)

Enter details of all outward supplies (sales) made during the period. Include invoice-wise details for B2B supplies and consolidated data for B2C supplies below ₹2.5 lakhs.

Step 4: File GSTR-3B (Summary Return)

Enter summary of outward supplies, ITC claimed on inward supplies, and compute tax liability. Make payment of net tax liability (after ITC adjustment) and submit the return.

Step 5: Download Acknowledgement

After successful filing, download the ARN (Application Reference Number) as proof of filing.

6. Important Due Dates

Return	Frequency	Due Date
GSTR-1 (Monthly)	Monthly	11th of next month
GSTR-1 (Quarterly - QRMP)	Quarterly	13th of month after quarter end
GSTR-3B (Monthly)	Monthly	20th of next month
GSTR-3B (Quarterly - QRMP)	Quarterly	22nd/24th of month after quarter end
GSTR-9 (Annual)	Annual	31st December

7. Penalties for Non-Compliance

Non-filing or late filing of GST returns attracts penalties:

• Late Fee: ₹50 per day (₹25 CGST + ₹25 SGST) for returns with tax liability
• Nil Return Late Fee: ₹20 per day (₹10 CGST + ₹10 SGST)
• Maximum Late Fee: ₹5,000 per return (reduced for small taxpayers)
• Interest: 18% per annum on outstanding tax liability
• Suspension of GSTIN: For non-filing of returns for 6+ months