Under the Goods and Services Tax (GST) framework, the nature of tax (IGST vs CGST+SGST) depends on the "place of supply" provisions read with the location of the supplier, as governed by the Integrated Goods and Services Tax Act, 2017.
In the present case:
As per Section 10(1)(b) of the IGST Act, where goods are delivered by the supplier to a recipient or any other person on the direction of a third person ("bill-to ship-to" model), it shall be deemed that the third person (i.e., the buyer in Karnataka) has received the goods, and the place of supply shall be the principal place of business of such third person.
Accordingly:
Place of supply = Karnataka
Location of supplier = Karnataka
Hence, the transaction qualifies as an intra-State supply under Section 8 of the IGST Act.
Therefore, levy of CGST + SGST is legally correct.
Further:
The fact that goods are physically delivered to Kerala does not alter the tax position due to the deeming fiction under Section 10(1)(b).
"Bill-to ship-to" invoicing is expressly recognized under GST law and is valid for e-invoicing compliance.
There is no mandatory requirement to charge IGST merely because the goods are delivered in another State, if the statutory conditions of Section 10(1)(b) are satisfied.
Conclusion:
Issuance of a "bill-to ship-to" invoice charging CGST and SGST is legally permissible and compliant. Raising an IGST invoice in this fact pattern would not be aligned with the place of supply provisions. This position is well-settled in law and supported by GST circulars and interpretative guidance.