Files on Clients

As a new coach who coaches via phone, 1-on-1, do you recommend keeping (anonymous) files on clients for life details? I had started a file just for basics (husband name, kids names, etc.) – but I find that each call is so encapsulated – I’m not expected to remember in-depth details every call. I find myself doing fine with just my basic memory and coaching on what comes up during the call. Any thoughts on keeping files on coaching clients?