RCW 62A.9A-314: Perfection by control.

(a) Perfection by control. A security interest in controllable accounts, controllable electronic records, controllable payment intangibles, deposit accounts, electronic documents, electronic money, investment property, or letter-of-credit rights may be perfected by control of the collateral under RCW 62A.7-106, 62A.9A-104, 62A.9A-106, 62A.9A-107, 62A.9A-1051, or 62A.9A-1071.

(b) Specified collateral: Time of perfection by control; continuation of perfection. A security interest in controllable accounts, controllable electronic records, controllable payment intangibles, deposit accounts, electronic documents, electronic money, or letter-of-credit rights is perfected by control under RCW 62A.7-106, 62A.9A-104, 62A.9A-107, 62A.9A-1051, or 62A.9A-1071 not earlier than the time when the secured party obtains control and remains perfected by control only while the secured party retains control.

(c) Investment property: Time of perfection by control; continuation of perfection. A security interest in investment property is perfected by control under RCW 62A.9A-106 not earlier than the time the secured party obtains control and remains perfected by control until:

(1) The secured party does not have control; and

(2) One of the following occurs:

(A) If the collateral is a certificated security, the debtor has or acquires possession of the security certificate;

(B) If the collateral is an uncertificated security, the issuer has registered or registers the debtor as the registered owner; or

(C) If the collateral is a security entitlement, the debtor is or becomes the entitlement holder.