If there is no entity, it can be sent directly to the mailbox. Just sign the contract according to the technical consultation. It will be enough to collect and settle foreign exchange according to non-trade items. (Enterprises pay business tax. In this case, they don't need to go to the customs for any import and export declaration. )

From the point of view of customs, I hope you can send some materials or USB flash drives, and then declare the consulting fee in the value of the materials, so that he can complete the purpose of collecting import tax. Enterprises pay import duties and value-added tax. VAT can be deducted)