11 CFR § 100.3 - Candidate (52 U.S.C. 30101(2)).
(a) Definition. Candidate means an individual who seeks nomination for election, or election, to federal office. An individual becomes a candidate for Federal office whenever any of the following events occur:
(2) The individual has given his or her consent to another person to receive contributions or make expenditures on behalf of that individual and such person has received contributions aggregating in excess of $5,000 or made expenditures aggregating in excess of $5,000.
(3) After written notification by the Commission that any other person has received contributions aggregating in excess of $5,000 or made expenditures aggregating in excess of $5,000 on the individual's behalf, the individual fails to disavow such activity by letter to the Commission within 30 days of receipt of the notification.
(4) The aggregate of contributions received under 11 CFR 100.3(a) (1), (2), and (3), in any combination thereof, exceeds $5,000, or the aggregate of expenditures made under 11 CFR 100.3(a) (1), (2), and (3), in any combination thereof, exceeds $5,000.
(b) Election cycle. For purposes of determining whether an individual is a candidate under this section, contributions or expenditures shall be aggregated on an election cycle basis. An election cycle shall begin on the first day following the date of the previous general election for the office or seat which the candidate seeks, unless contributions or expenditures are designated for another election cycle. For an individual who receives contributions or makes expenditures designated for another election cycle, the election cycle shall begin at the time such individual, or any other person acting on the individual's behalf, first receives contributions or makes expenditures in connection with the designated election. The election cycle shall end on the date on which the general election for the office or seat that the individual seeks is held.