Happy to help, just so I understand things fully: You have a client who purchases places orders on your store, from there, that client then sells the products to schools, who are tax exempt. So you want that client of yours to not be charged tax when they place an order on your store?
You can set up a tax exemption at the customer level so that that particular customer (email) doesn’t have tax charged to them when ordering. We have a guide on that here.
If there is anything else I can help you with, please let me know.
So in that case, my suggestion above would apply. He would have the school create their own customer account on his store, then he can set up a tax exemption at the customer level so that that particular customer doesn’t have tax charged to them when ordering. We have a guide on that here.