We've been having a really difficult time to implement EU-VAT validation in an automated way. I would like to share our experiences with other Viart users below.
 
EU VAT implementation is documented by Viart, however there are two key pieces of information missing.
 
1. To enable automatic checking and basket update as soon as a VAT number is entered, you need to add a line in the custom field properties in the "OnChange" Java section. Add this: document.order_info.operation.value='refresh';document.order_info.submit();
 
This will initiate automatic vat validation as soon as a number is entered.
 
2. EU VAT only works when you set your base pricing excluding VAT. There seems to be a bug where if you set base pricing inclulding VAT that Viart changes the excl. VAT price after entering a valid EU VAT number. This has been reported to Viart support.
 
Hope this helps others.

wow, this is exactly what I was looking for! Is thi really working? Where exactly do I have to insert that line?
thanks in advance,
ewoud

Hi,
 
Yes it works fine.
 
Point 1 needs to be implemented in "Order -> Order Profile Page -> Add New Custom Field".
 
Add a field called "EU-VAT Number" and set Field Type to "Shopping Cart" and Field Type to "TextBox". Set Show Field to "All Orders".
 
Then below in "JavaScript Settings", add the line as above in the "OnChange Event" section.
 
Click OK and you're all set!
 
The beauty of the way Viart implemented the VAT is that it checks the EU VAT database if the number is actually registered. This will prevent jokers from trying to get an illegal discount by entering a bogus number. As soon as a number is entered and the "OnChange" event is triggered, the VAT number is checked multiple times for consitancy and validity.
 
Hope this helps.
 
DickS

thanks, going to implement it right away! This shopping cart just does not stop to amaze me with all this flexibility! Great stuff!

Could you please tell me where is the EU VAT implementation documented by Viart?
I have looked, and there is no mention of it in the manual?
 
Regards,
 
Bela

Bela,
 
There is some rudimentary explanation which only covers part of the function. There is no description like above which we finally got implemented after a lot of investigation and trial and error.
 
DickS

I was able to find the explanation here:
 
https://www.viart.com/articles.php?category_id=3&search_category_id=3&search_string=vat

Ah, Viart added the automatic java checking routine :)