26 C.F.R. § 1.542-1
General rule
A personal holding company is any corporation (other than one specifically excepted under section 542(c)) which, for the taxable year, meets:
(a) The gross income requirement specified in section 542(a)(1) and § 1.542-2, and
(b) The stock ownership requirement specified in section 542(a)(2) and § 1.542-3.