What is the only way to perfect an interest in commercial deposit accounts?

To perfect a security interest in a commercial deposit account, a secured party must establish control over that account. This is because, under UCC Article 9, control is the method specified for perfecting an interest specifically in deposit accounts. Control can be achieved when the secured party becomes the bank's customer with respect to the deposit account, or through an authenticated record in which the bank agrees to comply with the secured party’s orders regarding the transfer of funds.

While filing a UCC-1 statement is applicable for many types of collateral, it does not apply to deposit accounts. The same is true for the suggestions of offering additional collateral or having a written agreement with the bank; these actions do not fulfill the specific requirement of perfection through control as outlined in the UCC. Thus, the correct and only method for perfecting an interest in a commercial deposit account is indeed by controlling the account.