Basic Uniform Commercial Code

Accession

UCC § 9-102(a)(1)

"Accession" means goods that are physically united with other goods in such a manner that the identity of the original goods is not lost.

E.g., like tires being put on a car.

Security interests remain attached and perfected in an accession. UCC § 9-335(a)–(b).

However, security interests in accessions are subordinate to security interests perfected by certificate of title. UCC § 9-335(d).