19 C.F.R. § 141.34
Duration of power of attorney
Powers of attorney issued by a partnership shall be limited to a period not to exceed 2 years from the date of execution. All other powers of attorney may be granted for an unlimited period.
Powers of attorney issued by a partnership shall be limited to a period not to exceed 2 years from the date of execution. All other powers of attorney may be granted for an unlimited period.