Subject to Article 3 concerning conversion of instruments (section 554.3420) and restrictive endorsements (section 554.3206) , only a collecting bank's transferor can give instructions that affect the bank or constitute notice to it, and a collecting bank is not liable to prior parties for any action taken pursuant to the instructions or in accordance with any agreement with its transferor.
Iowa Code § 554.4203
94 Acts, ch 1167, §90, 122