GST (Goods and Services Tax) compliance is mandatory for most online businesses in India, including e-commerce sellers, SaaS companies, digital service providers, and freelancers above the threshold. Understanding registration requirements, correct HSN/SAC codes, invoice formats, and filing obligations helps avoid penalties and keeps your business legally sound.
Who Needs GST Registration for Online Business?
GST registration is mandatory for:
- All e-commerce sellers — regardless of turnover, if selling through e-commerce operators (Amazon, Flipkart, Meesho)
- Businesses with turnover exceeding INR 20 lakh (INR 10 lakh for special category states) for service providers
- Businesses with turnover exceeding INR 40 lakh for goods suppliers
- Interstate suppliers — if you sell goods or services to customers in other states, regardless of turnover
- Businesses collecting tax at source (TCS) — e-commerce operators
Note: SaaS companies and digital service providers who sell to customers across India are typically making interstate supplies and must register regardless of turnover.
What Are HSN and SAC Codes for Online Businesses?
HSN (Harmonised System of Nomenclature) codes classify goods, while SAC (Services Accounting Code) codes classify services. Every GST invoice must include the correct code.
Common SAC Codes for Digital Businesses
| Service | SAC Code | GST Rate |
|---|---|---|
| IT software services | 998314 | 18% |
| Web hosting, domain registration | 998315 | 18% |
| Website design and development | 998314 | 18% |
| Digital marketing services | 998365 | 18% |
| SaaS / cloud computing | 998314 | 18% |
| Online advertising | 998365 | 18% |
| Training and coaching | 999293 | 18% |
| Consulting services | 998311 | 18% |
Disclaimer: GST rates and SAC codes are subject to change. Verify current rates on the CBIC (Central Board of Indirect Taxes and Customs) website or consult a tax professional before implementation.
What Must a GST-Compliant Invoice Include?
Every tax invoice issued by your online business must contain:
- Supplier’s name, address, and GSTIN
- Invoice number (unique, sequential)
- Date of issue
- Recipient’s name and address (and GSTIN if registered)
- HSN/SAC code of the goods or services
- Description, quantity, and unit of goods/services
- Total value before tax
- Tax rate and tax amount — CGST + SGST for intrastate, IGST for interstate
- Total value after tax
- Place of supply
- Signature or digital signature
For online businesses using WooCommerce or similar platforms, GST invoice plugins automate most of these requirements. Ensure the plugin you choose generates legally compliant PDF invoices.
What Are the GST Return Filing Requirements?
| Return | What It Contains | Frequency | Due Date |
|---|---|---|---|
| GSTR-1 | Outward supplies (sales) | Monthly or Quarterly (QRMP) | 11th of following month |
| GSTR-3B | Summary return with tax payment | Monthly or Quarterly (QRMP) | 20th of following month |
| GSTR-9 | Annual return | Annual | 31st December of following year |
| GSTR-9C | Reconciliation statement (if turnover > INR 5 crore) | Annual | 31st December of following year |
Businesses with turnover up to INR 5 crore can opt for the QRMP (Quarterly Return Monthly Payment) scheme, filing GSTR-1 and GSTR-3B quarterly while paying tax monthly.
How Does GST Apply to SaaS and Digital Products?
- SaaS sold to Indian customers: 18% GST applies. Issue invoice with SAC 998314. IGST for interstate sales (which most SaaS sales are, since the customer may be in any state)
- SaaS sold to foreign customers: Treated as export of services. Zero-rated under GST if: payment is received in convertible foreign exchange, supplier and recipient are in different countries, and the service is not performed in India. You can claim a refund of input tax credit on inputs used for these exports
- WordPress plugins and digital downloads: Classified as IT services, taxed at 18% GST
- Services received from abroad: If you use tools like AWS, Google Workspace, or Stripe, GST is payable under reverse charge mechanism (RCM) — you must self-assess and pay GST on these imports of services
What Are Common GST Compliance Mistakes Online Businesses Make?
- Not registering: Assuming small turnover exempts you when interstate sales make it mandatory
- Wrong SAC/HSN codes: Using incorrect codes leads to misclassification and potential penalties
- Mixing up IGST/CGST/SGST: Charging CGST+SGST on interstate sales or IGST on intrastate is incorrect
- Not reconciling ITC: Input Tax Credit must be reconciled with GSTR-2B data. Claiming ITC without matching invoices leads to notices
- Late filing: Late fees apply per day of delay. Interest at 18% per annum applies on outstanding tax
- Not issuing credit notes correctly: Refunds and returns require proper credit notes linked to the original invoice
What Tools Help With GST Compliance?
- Accounting software: Zoho Books, Tally, ClearTax, Vyapar — automate invoice generation and return filing
- WooCommerce plugins: GST invoice plugins generate compliant invoices with GSTIN, HSN/SAC codes, and tax breakup
- E-invoicing: Mandatory for businesses with turnover over INR 5 crore. Generate IRN (Invoice Reference Number) through the NIC portal or integrated accounting software
- E-way bill: Required for movement of goods worth over INR 50,000. Generate through the e-way bill portal
FAQ: Do I need separate GST registration in each state?
If you have a physical presence (office, warehouse) in multiple states, you need separate GST registration in each state. If you operate from one state and sell services to customers in other states, one GSTIN is sufficient — you charge IGST on interstate sales. E-commerce sellers using platforms that stock their products in multiple state warehouses may need multi-state registration.
FAQ: How do I handle GST on international SaaS subscriptions I pay for?
When you pay for services from abroad (AWS, Stripe, Adobe, etc.), you are liable to pay GST under the Reverse Charge Mechanism. You must self-assess the GST (typically 18%), pay it through your GSTR-3B return, and can then claim it as Input Tax Credit. Many businesses miss this, which can lead to issues during audits.
FAQ: Can freelancers and sole proprietors get GST registration?
Yes. Sole proprietors can register for GST using their PAN card. The process is entirely online through the GST portal. A separate legal entity is not required. However, if your turnover is below the threshold and you are not making interstate supplies, registration is optional. Voluntary registration allows you to claim input tax credit and appears more professional to clients.
