Tax ID - add to SHIP TO and SOLD TO sections of commercial invoice.

We started using ShipStation to ship our International orders, however, there is no field in ShipStation to add the customer’s tax ID in the SOLD TO section. I understand that is required on the commercial invoice, and thus we have to print out a paper copy of the commercial invoice and manually add that Tax ID so the shipment will clear. This would be a useful feature, and really required by UPS so should be on the electronic documents.