A couple one upgrades to a much larger iCloud account with plenty of space for his spouse to share with in a Family plan.
He sends the invite to join the family with her existing .Mac account but it still showing that she is using her old iCloud storage etc.
For the life of me I cannot find how to make this switch without loosing her vintage iCloud account or data.
She has to choose Use Shared Plan on her Mac or Use Family Storage on her iPhone or iPad in order to use the shared plan. Then, her data should be migrated to the Family Storage.
If a family member is already paying for their own iCloud+ plan, they can choose to switch to your plan or keep their own and still remain part of the family. When they switch to the shared family plan, they get a refund for the remainder of their personal plan. They can’t keep their current plan and use the shared family plan at the same time.
Switching to the Family Plan:
On your iPhone or iPad with iOS 17 or later, or iPadOS 17 or later
- Open the Settings app, then tap Family.
- Tap Subscriptions, then tap iCloud+.
- Tap Use Family Storage.
On your Mac with macOS Ventura or later
- Choose Apple menu > System Settings, then click Family.
- Click Subscriptions, then choose iCloud+.
- Click Use Shared Plan.