Right now the sales taxes in new york are 8.625%. When writing a proposal for a client do I charge this percentage just on on food and drinks or do I do my entire costing (rental and staff included) and then charge sales tax at the end of it all. I also charge a service chage of 15%.
The tax office told me I should charge like a restaurant, add all my cost and then chage taxes. Could someone in the know direct me. Don't want to do it wrong.

In a restaurant, you bill on the goods served correct? Everything from the tp in the bathroom to the staff's paychecks is paid for(hopefully)by selling that product. So in essense all costs are figured into the menu prices to pay bills and maybe make a buck or two. So if it costs you something to put out the food, you add that to you costs to the customer and charge the tax for the total cost of said product.

I think that gratuity when added to the bill is not taxed as it is a seperate fee/pay for labor not for the product but for services rendered.