My Customers Permission Set

Overview
Allows Administrators to change the permissions and settings of customer accounts

None: Prevents Customers from paying their invoice from the account.
Full: Allows Customers to pay invoices

None- Prevents sales reps from seeing customer accounts
View- Allows sales reps to view customer accounts
Create- Allows sales reps to create and view customer accounts
Edit- Allows sales reps to edit, create and view customer accounts

None: Prevents customers from viewing or changing subscription
View: Allows customer to view subscriptions
Edit : Allows customers to view and change their subscriptions

None- Prevents accounts from using and seeing custom actions.
Full- allows accounts to see and use custom actions as well as create. (Custom actions can be created in user actions).

You can now find an option in profile settings under My Customers  > Subscription Permission > Edit Limited to prevent parent account users from modifying child subscriptions when a child account is the direct invoice owner. The subscriptions remain visible, but the "Edit" button is disabled to ensure only the invoice owner can make changes.