@RCleaning I don't quite understand your question I'm afraid! 

When you've saved a clients card on file they receive an email notification with a link to their Card Dashboard. From this dashboard, a client can remove their card so it can't be used by you to process a payment. 

If a client does remove a card you'll receive an email to let you know and their card information will automatically be removed from your online Square Dashboard and the Point of Sale app.

Let me know if you're having trouble with card on file and I'll be happy to help!