Chosen Solution
I have a customer that has 2 apple accounts. 1 that he has used for several years ( nothing purchased on it that is needed ) and a new 1 setup recently by his son that has paid for storage and other things he wants to keep. Account 1 ( had for years ) is signed into his imac, hasnt got icloud enabled or used, all data is local on his imac. there is about 700GB of user data Account 2 ( is a few months old ) is signed into his new phone, has about 100GB data and is using icloud. the plan is to use the older iMac with his new icloud account and leave the phone as it is. i am just checking the possible pitfalls going into this blind. things like his total icloud storage on the new account is 200GB, i presume he will need to purchase the 2TB one if we are putting an additional 700GB into it or untick his photos from backups.
I would make the effort to talk with Apple on the Pro’s n’ Con’s on merging the two accounts. It might make sense getting a family plan so there is one payment keeping both accounts (setting his iMac as a shared system to the full family and yet hold some data private. If the issue is the iCloud data you can alter the iCloud account storage permissions so access from the other account is possible Manage your iCloud storage Here’s more from Apple: Share iCloud+ with your familyChange iCloud Storage preferences in Family Sharing on MacWhat you can do with iCloud storage I have no knowledge on this app but it might help: How to Merge Two or Multiple iCloud Accounts into One
