If you need to add Sales Tax to your customers documents, you need to make sure the customer is set to be 'VAT Applicable'
Sales Tax based on your National Rate will now be added to all future orders, proformas and invoices for this customer, at your country's rate. For existing Sales Orders, Proformas and Invoices you will need to Update Customer Field (if you deselected the field the tax will be removed)
For EU Clients:
You need to check if the Sales Tax number is valid to create correct EC Sales List
Input the tax number with the country prefix, then you can click the grey button for Zedonk to verify and confirm the number online.
This can be done in the individual documents by selecting red [Update!] prompt
