Communication error with the external tax system

在创建Vendor主数据时(国家选择了US)，系统产生错误信息Communication error with the external tax system

原因是应用了vertex

In the US the tax system is very complicate and therefore tax
determination is not done within SAP.
Just as an explanation. The tax rate might be different in each state.
Well that's normal and no problem for SAP. But the tax rate can be
different between the cities in the same state and if it comes worse the
rate various depending on the street where the customer is located.
In the same complex way the product might be taxable and sometimes not
taxable depening what kind of customer is ordering this product.

SAP recommends 3 products: Sabrix, Taxware and Vertex

One important thing for the taxdetermination is the so called "tax
jurisdiction code". This code will be determined based on the customers
address (state, city and sometimes even street). SAP uses RFC calls and
is transfering this information to Vertex and Vertex is responding with
the jurisdication code.

I don't know who has setup your system for the US market but normally it
is standard that you get an error message during customer master
maintenance if the connection between SAP and Vertex is not working.

I doubt that you can run SAP for the US without Vertex, Sabrix or
Taxware.
You have to fix the communication problem.

For details about the configuration please look at the SAP document:

"R/3 Tax Interface Configuration Guide"