8 C.F.R. § 233.4

(a) Form I-425 agreements. A transportation line bringing applicants for admission to the United States through preinspection sites outside the United States shall enter into an agreement on Form I-425. Such an agreement shall be negotiated directly by the Service's Headquarters Office of Inspections and the head office of the transportation line.

(b) Signatory lines. A list of transportation lines with currently valid transportation agreements on Form I-425 is maintained by the Service's Headquarters Office of Inspections and is available upon written request.