You can now put a licence number, an activity certificate or a personal identification code in a new Additional information field. Whatever you type there prints under your business details, worded exactly as you entered it.
Not every business has a company code. Someone trading as an individual in Lithuania invoices under an activity certificate number and activity codes, and an Icelandic sole trader under a personal identity code. Plenty of businesses also carry a licence number their invoices have to show. Until now the only place for those was Registration number, which takes one company code and nothing else.
Open Business settings and you will find the new field on the Company profile tab, under VAT & Registration. Your customers have the same field, so a number a customer asks you to include prints under their details instead. See Adding a licence, certificate or personal code to your invoices for the details.
A Finnish business now shows Y-tunnus on its invoices in place of the generic term, a Czech one IČO and a Danish one CVR-nr. The name comes from the register that issued the number, so an invoice calls it what its reader would search for.
Where a register publishes that name in more than one language, the reader's own is used: Finland's is officially Business ID in English and FO-nummer in Swedish. Where a register has no name in the reader's language, its own stands, so a Finnish business invoicing in Estonian still shows Y-tunnus.
Your customers' numbers follow the same rule, so one invoice can carry two different names, each correct for the business it sits under.