First of all, it should be noted that withholding taxes at EMDI, is considered any document line that is defined as an add-on with zero VAT and negative price.
In order to make a deduction or charge I must first make a price list from the settings.
In this example I make a charge as a price list in the pricelist settings and then set the rate of the charge/deduction from the categories pricelist.
Then I have to make a product with a Product handle the name of the charge, add a description, the measurement unit has to be addoon and put a category.
Next step is to go to Purchases / Sales and make a document with a product or service.Then I right click inside document to open the menu and select Calculations, select the charge I want and then the create button.
There is also the possibility of analyzing the charges in the printing using the variables #LOI, #LPF, #LPP. More information here.
Be careful not to use the symbols . , # !)( in the VAT description