For the holder of a POA the CIP Frequently Asked Questions says:
"1. Who is the “customer” when an account is opened by an individual who has power-of- attorney for a competent person who is the named owner of the account?
The CIP rule provides that a “customer” generally is “a person that opens a new account.” 31 C.F.R. § 103.121(a)(3)(i)(A). When an account is opened by an individual who has power-of-attorney for a competent person, the individual with a power-of-attorney is merely an agent acting on behalf of the person that opens the account. Therefore, the “customer” will be the named owner of the account rather than the individual with a power-of-attorney over the account. By contrast, an individual with power-of-attorney will be the “customer” if the account is opened for a person who lacks legal capacity. 31 C.F.R. § 103.121(a)(3)(i)(B)(1)."
CIP FAQs