GST on GST

If he is acting as a pure agent then no gst is leviable on reimbursement... Plz refer section 15...gst is leviable only on his advertising fee

No. He is not pure agent.. Only collected his actual spend

Pure Agent means a person who: (a) enters into a contractual agreement with the recipient of supply to act on their behalf and incur expenditure or costs in the course of supply of goods or services or both; (b) neither intends to hold nor holds any title to the goods or services (or both) procured on behalf of or provided to the recipient of supply; (c) does not use the goods or services so procured for his own interest; and (d) receives only the actual amount incurred to procure such goods or services.

If all that expenses is on ur account and bill is in ur name... Just payment made by that person and later u reimburse the same... Then no gst on it... Refer rule 33 of cgst act... In future make bill in ur own name

Thanks for ur clarification