Why There Are Three Components
India’s GST has three components because both the central and state governments levy the tax, and because supplies can happen within a state or across state lines. CGST is the central component, SGST is the state component, and IGST is the integrated component for transactions that cross state boundaries. Rather than being three separate taxes the customer pays in addition to one another, they are the way a single GST liability is divided depending on the nature of the transaction. Which components apply to a given supply depends entirely on whether it is intra-state or inter-state, so identifying the type of supply correctly is the first step.
CGST and SGST on Intra-State Supplies
When a supply takes place within a single state, meaning the supplier and the place of supply are in the same state, the GST is split into CGST and SGST. The total tax rate for the item is divided into equal central and state halves, both charged on the same transaction and shown separately on the invoice. The CGST portion goes to the central government and the SGST portion to that state. For the business, the combined CGST and SGST equals the applicable GST rate, and both are recorded distinctly so each government receives its share and the amounts can be reported correctly in returns.
IGST on Inter-State Supplies and Imports
When a supply crosses state lines, or in the case of imports, a single integrated tax called IGST applies instead of the CGST-plus-SGST split. IGST is charged at the full applicable rate as one component. It is collected by the central government and subsequently apportioned so that the destination state receives its share, consistent with GST being destination-based. Treating an inter-state supply as if it were intra-state, or vice versa, is a common error that leads to charging the wrong components and creates reconciliation problems later. Determining the correct place of supply is therefore central to applying IGST properly.
How Credit Works Across the Components
Input tax credit interacts with these components according to rules about which credit can offset which liability. Broadly, the system allows the tax paid on purchases to be used against the tax due on sales, with an order and conditions governing how IGST, CGST, and SGST credits are applied against the respective liabilities. The practical effect is that a business accumulating one type of credit can often use it against the appropriate liabilities, but the set-off follows defined rules rather than being entirely free-form. Because these rules can be intricate and are subject to change, accurate records of each component are essential for claiming credit correctly.
Getting It Right on Invoices
Applying the components correctly comes down to determining the place of supply for each transaction and then charging CGST and SGST for intra-state supplies or IGST for inter-state supplies, at the applicable rate, clearly itemized on the invoice. Mistakes here ripple into returns and credit claims, so consistency matters. Accounting software that knows the supplier and customer locations can apply the right components automatically, reducing manual error. HelloBooks supports GST-compliant invoicing that distinguishes intra-state and inter-state supplies, helping ensure each invoice carries the correct components, while the applicable rates themselves should follow current GST law.