De Facto Officer refers to an officer holding a colorable right or title to the office accompanied by possession. The lawful acts of an officer de facto, so far as the rights of third persons are concerned, when done within the scope and by the apparent authority of office, are valid and binding.
The de facto officer doctrine confers validity upon acts performed by a person acting under the color of official title even though it is later discovered that the legality of that person’s appointment or election to office is deficient.
The following is case law defining the term De Facto Officer. “An officer de facto is one whose acts, though not those of a lawful officer, the law, upon principles of policy and justice, will hold valid so far as they involve the interests of the public and third persons, where the duties of the office were exercised:
First, without a known appointment or election, but under such circumstances of reputation or acquiescence as were calculated to induce people, without inquiry, to submit to or invoke his action, supposing him to be the officer he assumed to be;
Second, under color of a known and valid appointment or election, but where the officer had failed to conform to some precedent requirement or condition, as to take an oath, give a bond, or the like;
Third, under color of a known election or appointment, void because the officer was not eligible, or because there was a want of power in the electing or appointing body, or by reason of some defect or irregularity in its exercise, such ineligibility, want of power, or defect being unknown to the public;
Fourth, under color of an election or appointment by or pursuant to a public unconstitutional law, before the same is adjudged to be such”. [Jersey City v. Dep't of Civil Serv., 57 N.J. Super. 13, 27 (App. Div. 1959)]