The Company Name needs to be populated for VAT to display. So you need to populate Company Name and VAT. Within CBSubs it serves no purpose beyond business usage (CBSubs Tax) and isn't passed to most payment gateways as they've no use for it.

I don't understand, you want VAT or you don't want VAT? If you don't want VAT then you can try removing it from the XML file below, which determines the display of the invoice address form.

/components/com_comprofiler/plugin/user/plug_cbpaidsubscriptions/xml/edit.front.invoice.xml

VAT has no purpose beyond CBSubs Tax. Most gateways don't have VAT so we only send address, country, city, state, and zip if possible (but not required by any gateway).

For VAT to work the "Company" must have a value. Note when you populate these fields with a value it does not fire the jQuery when going to invoice address (this is a known bug) so you need to click or change the value of "Company" to trigger the jQuery so VAT will show.

Tax is geo location based. VAT is only used for "European Union Tax settings" under the Tax settings. So you can have location by location tax usage perfectly fine without VAT. Please see your CBSubs documentation for CBSubs Tax usage information.