Out of pocket is another transatlantic split. In American workplace usage it means unavailable or unreachable: “I’m out of pocket until Thursday”. In British and Commonwealth usage it means bearing a cost personally: “the travel left me out of pocket”. Both senses are current, in different rooms.
Context usually rescues the listener, but the American sense reliably confuses UK and Australian colleagues on first contact. If your team spans regions, the unambiguous alternatives are free: “unavailable” and “paying personally” both survive the Atlantic intact.