UK Can they "claw back" Council Tax Benefit without telling you first?

You must be notified of an overpayment - or any change to your benefit - and the intention to recover it, this normally happens automatically from the computerised benefit system on the day the decision is made. You have one month from the date of notification to either ask for the decision to be looked at again, provide any relevant evidence, and/or appeal.

If you dispute the overpayment then you must ask for recovery action to be held pending any reconsideration or appeal as this may not happen unless you specifically ask - a phone call or email should do it. Don’t forget to keep a record of all contact with them, dates, names, what was said or agreed etc, from this point onwards....