11 CFR §102.12

1. (a)Each candidate for Federal office (other than a nominee of a political party to the Office of Vice President) shall designate in writing a political committee to serve as his or her principal campaign committee in accordance with 11 CFR 101.1(a) no later than 15 days after becoming a candidate. Each principal campaign committee shall register, designate a depository and report in accordance with 11 CFR parts 102, 103 and 104.
2. (b)No political committee may be designated as the principal campaign committee of more than one candidate.
3. (c)
   1. (1)No political committee which supports or has supported more than one candidate may be designated as a principal campaign committee, except that, after nomination, a candidate for the office of President of the United States nominated by a political party may designate the national committee of such political party as his or her principal campaign committee. A national committee which is so designated shall maintain separate books of account with respect to its function as a principal campaign committee.
   2. (2)For purposes of 11 CFR 102.12(c), the term support does not include contributions by an authorized committee in amounts aggregating $2,000 or less per election to an authorized committee of any other candidate, except that the national committee of a political party which has been designated as the principal campaign committee of that party's Presidential candidate may contribute to another candidate in accordance with 11 CFR part 110.