on demand

noun | de·mand

1. : a formal request or call for something (as payment for a debt) especially based on a right or made with force a shareholder must first make a demand on the corporation's board of directors to act —R. C. Clark a written demand for payment

2. : something demanded any demands against the estate — see also claim

transitive verb

1. : to ask or call for with force, authority, or by legal right : claim as due on any issue triable of right by a jury, a party may demand a jury trial —Federal Rules of Civil Procedure Rule 38(b)