National Equipment Rental, Ltd. v. Szukhent, 375 U.S. 311 (1964), was a case in which the Supreme Court of the United States held that service of process upon a party's designated agent does not invalidate personal jurisdiction that would otherwise be established, if the agent gives prompt notice to the party.

), National Equipment Rental served process upon Ms. Weinberg, who then notified the Szukhents of the suit via mail.

[7] Justice Black dissented, and would have found the agency relationship invalid by applying of New York state appellate court precedent, thus affirming the District Court's quashing of service.

Alternatively, if defining agency law for the purposes of the Federal Rules of Civil Procedure, Justice Black would not include the relationship in question in such a definition.

Finally, Justice Black questioned whether the Szukhents had received due process under the Fifth and Fourteenth Amendments, which form parts of the basis for Constitutional personal jurisdiction jurisprudence.