After the customs declaration, the foreign trade agency shall go through the tax refund formalities with the bank receipt, customs declaration and other documents. As for who the tax refund belongs to, both parties can negotiate that the tax refund as a formal agent belongs to you, and if the tax refund as a buyout agent belongs to a foreign trade company, you have settled the tax refund in advance.
Of course, it is cost-effective not to invoice, but it is illegal. How to do financial accounts?