# Treas. Reg. § 1.1504-1: Definitions.

Source: eCFR as of 2026-10-19 <https://www.ecfr.gov/current/title-26/section-1.1504-1>. Interprets 26 U.S.C. § 1504.

The privilege of filing consolidated returns is extended to all includible corporations constituting affiliated groups as defined in section 1504. See the regulations under § 1.1502 for a description of an affiliated group and the corporations which may be considered as includible corporations. 

[T.D. 6500, 25 FR 12106, Nov. 26, 1960]