Final answer:
In addition to an AIF and MDN, a signed contract is required to legally on-board an account requiring a contractual agreement.
Step-by-step explanation:
When on-boarding an account that requires a contract, an additional document required is the signed contract itself. The Account Information Form (AIF) and Master Direction Note (MDN) gather necessary details, but the signed contract is crucial as it legally binds the parties to the terms agreed upon. It should outline the services, terms, and conditions, fees or payments, and responsibilities of each party. This document must be reviewed and ratified to ensure all legal obligations are clear and acknowledged.