A. The Concept of Value Addition:
In traditional sales taxation, tax was levied on the total selling price at every stage of sale, resulting in a cascading tax effect (tax on previously collected tax). Under the Value Added Tax (VAT) / Goods and Services Tax (GST) regime, tax is collected at each stage of the supply chain, but businesses are permitted to claim credit for the tax already paid on their purchases. Thus, tax is effectively levied only on the value added by each intermediary.
$$\text{Value Addition} = \text{Selling Price (SP)} - \text{Cost Price (CP)}$$ $$\text{Tax on Value Addition} = \text{Tax Rate} \times (\text{SP} - \text{CP}) = \text{Output Tax} - \text{Input Tax}$$B. Intra-State vs Inter-State Transactions:
| Transaction Type | Jurisdiction | Applicable Taxes | Mathematical Formula |
|---|---|---|---|
| Intra-State Supply | Buyer and Seller reside in the same State or Union Territory. | Split equally between Central Govt (CGST) and State Govt (SGST/UTGST). | $$\text{CGST} = \frac{1}{2} \times \text{GST Rate} \times \text{SP}$$ $$\text{SGST} = \frac{1}{2} \times \text{GST Rate} \times \text{SP}$$ |
| Inter-State Supply | Buyer and Seller reside in different States or Union Territories. | Entire tax collected by Central Govt as Integrated GST (IGST). | $$\text{IGST} = \text{GST Rate} \times \text{SP}$$ $$\text{CGST} = 0, \quad \text{SGST} = 0$$ |