19 C.F.R. § 141.44
Unless a power of attorney specifically authorizes the agent to act thereunder at the appropriate Center and at all CBP ports, the name of the appropriate Center or each port where the agent is authorized to act thereunder shall be stated in the power of attorney. The power of attorney shall be filed with CBP, either at the port of entry or electronically, in a sufficient number of copies for distribution to the appropriate Center and each port where the agent is to act, unless exempted from filing by § 141.46 . The Center director or port director with whom a power of attorney is filed, irrespective of whether his Center or port is named, shall approve it, if it is in the correct form and the provisions of this subpart are complied with, and forward any copies intended for other ports or another Center as appropriate.
19 C.F.R. §141.44