Credits can only be added to a family account by cancelling the registration, please see Refund to an Account Credit Balance.
Credits can be used to pay a balance from your admin site or the customer's online account.
- From admin site: see How to Use Credit Balance on Admin site
- From customer's online account: see How to Use Credit Balance on Participants End
To remove the credit from a family account without issuing a refund, you can set an expiration date for the credit, refer to Edit Credit Balance Expiry Date