In the link below you can check the information you need for Finland companies

verkkolaskuosoite.fi/client/index.html#/

If you are registered for VAT in Finland, the VAT number is formed using the country code FI and a string of digits that is the same as the Business ID without the dash between the two last digits. For example, if the Business ID is 0765432-1, the Finnish VAT number is FI07654321.