Because in Greece we are more advanced than all other countries on the planet, especially in our tax system, we created a plugin for woocommerce where the customer can choose at checkout if he wants an invoice or receipt. If the customer chooses invoice the fields VAT, tax office and activity are displayed and marked as mandatory. There was a plugin which until now did what we wanted but the problem was that it did not put these fields in the customer's tab in the back-end and while they were displayed in the order again in the back end did not allow the admin to edit them, so we added these features to our plugin, so for example if the admin wants to pass a phone order to be able to pass the invoice details ........ the Plugin can be installed like all other wordpress plugins from here https://wordpress.org/plugins/timologia-for-woocommerce/