For ages we have had a Registration No. field in table Company Information but no such field in Customer or Vendor table.

Due to that almost every BC localization I have seen (Finnish, Estonian, Latvian, Russian ...) has made their own Reg.no. field.

It's time to add Registration No. field to Customers and Vendors at least for W1 version.

Every company in many countries have mandatory Registration No. - so it can be used as unique identifier if needed etc.
Currently in BC we have VAT Registration No. field, but not every company is registered to use VAT.