What is the main business cost of advertising, and under what circumstances can it be deducted?

1. When doing business activities for customers, buy some supplies, such as flowers, lottery supplies, salute, etc. Are these things included in the main business cost or operating expenses when invoicing? Can these expenses be deducted from income when paying business tax?

You can't.

2. The customer asks for short message service (just like the XX place where our mobile phone usually receives XX service). The customer charges 10000 yuan, and we give the technology company 5000 yuan to collect the information service fee sent by them. Can this situation be regarded as "agency industry"? Can I use the (income-expenditure) * tax rate when paying business tax?

You can't.

Attachment: For those engaged in advertising agency business, the taxable turnover shall be the balance of their total income minus the advertising fees paid to other advertising companies or publishers (including media and carriers).