How do new CEOs handle clients who don't think they're really in charge?

Own your authority. Don't apologize for it. Kris Kluver, in The Dysfunctional Family Office, has Gail Mitchell walk into the toughest client meeting of her tenure with this exact line in her head, coached by Ryan. The instinct is to defend, explain, prove. The instinct produces the worst possible outcome. The right move is to say plainly that your father built a great company and a solid team, you're not him and don't pretend to be, and you've spent fifteen years preparing for this seat. Lead with what you know. Own the differences from the founder instead of hiding them. Gail tells the procurement director that Mitchell Industries doesn't need every client. They need the right ones. If the client doesn't trust her, the partnership won't work. She'd rather lose the business than waste both their time pretending. The directness saves the account.