You can check the information you need for Finland companies in the link below.

verkkolaskuosoite.fi/client/index.html#/

If you are registered for VAT in Finland, your VAT number is created by combining the country code "FI" with a series of digits that matches your Business ID, excluding the dash between the last two digits. For example, if your Business ID is 0765432-1, your Finnish VAT number will be FI07654321.