Why must international wire transfers be verbally approved by banks and how do fees differ from standard transfers?

Rules are changing from bank to bank. International wire transfers are now seen as a higher-risk transaction by many banks. Compliance programs and FATF guidelines have pushed everything into being overly cautious (IMHO).

You have to call the bank to be sure the funds transfer is approved by you. Many accounts can be compromised, and fake international transfers can be done. Banks generally have a better perspective on the frequency of such kinds of fraud and hence the SOP to call it in.

The fees can vary in many different way, but predominantly, this is the correspondent banking fees along with the SWIFT wire transfer fees that is being implemented here.