Principal Office
Principal Office means the location where the greatest number of the concern's employees at any one location perform their work. However, for those concerns whose primary industry (see 13 CFR 121.107) is service or construction (see 13 CFR 121.201), the determination of principal office excludes the concern's employees who perform the majority of their work at job-site locations to fulfill specific contract obligations.
Source
13 CFR § 108.50
Scoping language
The following definitions apply to this part 108: