Please note that the place of supply is determined based on the state code mentioned in the customer’s GSTIN, which represents the customer’s billing location.
As per Section 10(1)(b) of the IGST Act, in a Bill To – Ship To transaction, the place of supply is considered to be the location of the person to whom the invoice is issued (billing address), even if the goods are delivered to a different location.
For more information, please refer to the blog on Understanding the Place of Supply:
https://getswipe.in/blog/article/place-of-supply-of-goods