The UCC covers security interest pertaining to goods but not services. In the recent Sires case, plaintiff bought and rendered services for defendant, expecting to be reimbursed by them pursuant to an express agreement. That agreement was expressed in the course of dealing between the two parties. Defendant did reimburse plaintiff several times under that agreement, and made an express offer to reimburse at the time in question.
Plaintiff was unjustly enriched because while plaintiff was never reimbursed for the purchases, plaintiff bought services for defendant under an express agreement. The plaintiff could not recover against defendant under a theory of laches because the plaintiff had an express contract with a surety regarding identical subject matter. That theory of law is based on contract principles. An implied contract and an express one covering the identical subject matter cannot exist at the same time. If one exists the other is necessarily precluded.
