Do i need a contract?
Yes it’s best if you use a contract, mainly to assure yourself of being paid by the investor wants you have located a qualifying property. You should also prepare questionaire to determine exactly what areas and what type of properties they are looking for. As well you want to know if they have the funds to close on the the property, if they don’t they are wasting your valuable time. Then wants they close that is when you get paid your finders fee. So yes make sure you have your agreement in writing.
From my experience in many cases you don’t really need a contract as long as you have a certain level of trust with the investor. Most investors don’t want to bite the hand that feeds them leads.