Which type of deposit account is governed by UCC Article 9?

Commercial deposit accounts are governed by UCC Article 9 because this part of the Uniform Commercial Code addresses secured transactions, including the use of deposit accounts as collateral. Under UCC Article 9, a "deposit account" is defined specifically and typically refers to an account maintained at a bank that may be used as collateral in secured transactions.

Article 9 primarily affects commercial transactions involving businesses, which is why commercial deposit accounts fall under its purview. In contrast, personal, shared, and joint deposit accounts generally do not involve the same level of commercial activity or are not used in the context of secured financing arrangements that UCC Article 9 regulates. Thus, while these other types of accounts might be relevant in broader banking contexts, they are not specifically addressed within the framework of UCC Article 9 as commercial deposit accounts are.