19 CFR §181.73

1. (a)Written notification required. Prior to conducting a verification visit in Canada or Mexico pursuant to § 181.72(a)(2)(iii) of this part, Customs shall give written notification of the intention to conduct the visit. Such notification shall be delivered:
   1. (1)By certified or registered mail, or by any other method that produces a confirmation of receipt, to the address of the Canadian or Mexican exporter or producer whose premises are to be visited;
   2. (2)To the customs administration of the country in which the visit is to occur; and
   3. (3)If requested by the country in which the visit is to occur, to the embassy of that country located in the United States.
2. (b)Contents of notification. The notification referred to in paragraph (a) of this section shall include:
   1. (1)The identity of the Customs office and officer issuing the notification;
   2. (2)The name of the Canadian or Mexican exporter or producer of the good, or producer of the material, whose premises are to be visited;
   3. (3)The date and place of the proposed verification visit;
   4. (4)The object and scope of the proposed verification visit, including specific reference to the good or material that is the subject of the verification;
   5. (5)The names and titles of the Customs officers performing the proposed verification visit;
   6. (6)The legal authority for the proposed verification visit; and
   7. (7)A request that the Canadian or Mexican exporter or producer of the good, or producer of the material, provide its written consent for the proposed verification visit.