E-Commerce GST Calculation Guide & Input Tax Credit (ITC)
Understanding reverse GST extraction formulas, intra-state CGST/SGST splits, and claiming Input Tax Credit on seller fees.
1. Extracting Base Price from GST Inclusive Slabs
When product retail prices are listed as "GST Inclusive", calculating exact net revenue requires extracting the embedded tax component. The formula is: Base Price = Gross Inclusive Price / (1 + (GST Rate / 100)). For example, a $118 GST-inclusive product at 18% GST yields a base price of $100 and a tax amount of $18.
2. CGST, SGST, and IGST Tax Component Mechanics
For sales completed within the seller's home state (intra-state), total GST is split equally into 50% CGST (Central Goods & Services Tax) and 50% SGST (State Goods & Services Tax). For inter-state shipments across state lines, 100% of the tax is charged as IGST (Integrated Goods & Services Tax).
3. Claiming Input Tax Credit (ITC) on Marketplace Fees
E-commerce platforms (such as Amazon, Flipkart, and Meesho) charge 18% GST on all seller referral fees, closing fees, and FBA storage surcharges. Online sellers with active GST registration can claim Input Tax Credit (ITC) on all marketplace fees and logistics invoices, reducing total monthly tax liability.