GST compliance is one of the most important operational requirements for Indian businesses — this guide demystifies it for business owners who are not accountants.
GST Registration: When You Must Register
Mandatory GST registration thresholds in India: businesses with annual turnover above ₹40 lakh (goods) or ₹20 lakh (services) in most states. For special category states (northeast India, Himachal Pradesh, Uttarakhand, Jammu & Kashmir), threshold is ₹20 lakh for goods and ₹10 lakh for services.
Mandatory registration regardless of turnover: any business making inter-state supplies (selling products to customers in states other than your business location), e-commerce businesses, or businesses supplying through e-commerce operators (Amazon, Flipkart, Meesho) must register for GST even at turnover below the threshold.
Voluntary registration: even below the threshold, registering for GST voluntarily has advantages: ability to issue GST invoices (required by B2B customers who want Input Tax Credit), ability to claim ITC on your business purchases, and credibility in B2B markets where registered suppliers are preferred.
Registration process: apply online at gst.gov.in. Required documents: PAN, Aadhaar, bank account with IFSC, business address proof, and business registration documents. Registration is typically completed in 3-7 working days.
GST Filing Requirements
Monthly filers (businesses above ₹5 crore annual turnover): GSTR-1 (outward supply details) by 11th of every month; GSTR-3B (summary return with tax payment) by 20th of every month.
Quarterly filers (businesses below ₹5 crore — QRMP Scheme): GSTR-1 quarterly by 13th of October, January, April, July; GSTR-3B quarterly by 22nd or 24th of October, January, April, July (date varies by state). Monthly payment via PMT-06 if you have tax liability.
Annual return: GSTR-9 (annual return) by 31st December of the following financial year. GSTR-9C (reconciliation statement) required for businesses above ₹5 crore annual turnover.
Practical tips: reconcile your purchase register with GSTR-2B (auto-generated purchase return) every month before filing GSTR-3B. Discrepancies must be investigated and resolved — claiming ITC not reflected in GSTR-2B creates scrutiny. Maintain systematic invoice records (both sales and purchase) month-wise to make filing efficient.
Input Tax Credit: Reducing Your Tax Liability
Input Tax Credit (ITC) allows you to offset the GST you have paid on business purchases against the GST you collect from customers. This prevents the cascading effect of tax-on-tax. Example: you collect GST of ₹18,000 from customers this month. You paid GST of ₹8,000 on your business purchases (office supplies, software, professional services). Your net GST payment = ₹18,000 - ₹8,000 = ₹10,000.
ITC eligibility rules: ITC can be claimed only on purchases used for business purposes. Not eligible: personal consumption, blocked credits (defined in Section 17(5) of CGST Act) including food and beverages, cosmetics, and certain others. Your supplier must have filed their GSTR-1 and the purchase must appear in your GSTR-2B for ITC to be eligible.
Managing ITC: prompt payment to suppliers (within 180 days to retain ITC eligibility), regular reconciliation with GSTR-2B, and working with suppliers who file their returns on time (suppliers who do not file returns block your ITC). Using GST-compliant accounting software (Zoho Books, Tally) that automatically reconciles ITC is strongly recommended for any business with significant purchase volumes.
Frequently Asked Questions
What are the penalties for late GST filing in India?
Late filing penalties: GSTR-1 late fee: ₹50/day (₹25 CGST + ₹25 SGST) for businesses with turnover above ₹1.5 crore; NIL for businesses below ₹1.5 crore but late fee waiver schemes are available. GSTR-3B late fee: ₹50/day (₹25 CGST + ₹25 SGST) with a maximum of ₹10,000 for businesses with turnover above ₹5 crore; for smaller businesses, maximum late fee is ₹500. Additionally, interest at 18% per annum applies to delayed tax payments. Consistent late filing attracts GSTN scrutiny notices.
Do I need an accountant/CA to file GST?
For businesses with simple GST situations (one GST rate, few transactions, no ITC complexity), GST filing can be done by the business owner through the GST portal's self-service interface. The government also provides GSTN-approved accounting software with filing integration. However, for: multiple GST rates, significant ITC claims, export transactions, e-commerce marketplace selling, or any business above ₹1 crore turnover, engaging a CA or GST practitioner is strongly recommended. The CA's fee (typically ₹1,500-₹5,000/month for regular compliance) is a business expense and far cheaper than penalties and notices arising from filing errors.