Force customer to insert VAT number

[Karakko]

Hello, I would like to force customer to insert VAT number if he wants to access to a "special price list" only available to corporations.
It's the same list of product available to normal customers, but they have to be linked per quantity.
How can I do this ?
Thank you so much for your time spending on reading this.
 

[tuk66]

Use the European VAT number module to force it. Then you can create a condition in the code to show or not to show the list.