The GSTIN is used by the system to calculate the CGST, SGST, IGST, or UGST. If the location of the vendor and the location of the client is in the same state (Intra-state) then CGST and SGST will be calculated and if the location of both is in a different state (Inter-state) then IGST will be charged at the time of raising PO and Direct Invoice.
If the location of the customer and company’s location is in the same state (Intra-state) then CGST and SGST will be calculated and if the location of both is in a different state (Inter-state) then IGST will be charged at the time of Sales Invoice.