Ariz. Rev. Stat. § 33-818
Except as otherwise provided in this section, a trust deed, substitution of trustee, notice of resignation of trustee, assignment of a beneficial interest under a trust deed, notice of sale, cancellation of notice of sale, trustee's deed, deed of release, and any instrument by which a trust deed is subordinated or waived as to priority, if acknowledged as provided by law, shall from the time of being recorded impart notice of the content to all persons, including subsequent purchasers and encumbrancers for value. The recording of an assignment of the beneficial interest in a trust deed shall not be deemed notice of such assignment to the trustor, his heirs or personal representatives, so as to invalidate any payment made by them, or any of them, to the person previously holding the note, bond, or other instrument evidencing the contract or contracts secured by the trust deed.
A.R.S. § 33-818