TransferWise serves over 300 transfer routes. You can learn more about the countries TransferWise supports here.
It depends on the country you're sending money to. In the Eurozone, you'll always need an IBAN and a SWIFT BIC code. Banks in the USA use SWIFT codes, but they don't use IBANs. It's the same in New Zealand too. Learn more about IBANs here.
As of today, 35 countries in the extended Eurozone are within the SEPA (Single European Payments Area) - including the United Kingdom, Switzerland and Germany. Learn more about which countries are in the SEPA here.
TransferWise takes no responsibility for any money you lose because you’ve used the wrong code.
If you’re not sure about any of the details you’re using, get in touch with the bank or financial institution in question. They should be able to give you the right information.