When I was working in the banking sector a lot of employees were provided with mobile phones to conduct business. If nowadays there is a requirement to record everything, how are voice calls are saved? In general for mobiles and in case of IPhones specifically.
Where I work you absolutely can't use a mobile phone to conduct business. Traders have dedicated lines and those are recorded. Traders also have chats which are also saved. The rest of staff uses teams or whatever. I assume that's recorded as well, but no one cares if you use something else.