Non Binding Agreement
Legal Contracts - Under state laws, only a few category of contracts must be in writing, such as a mortgage contract or contracts covering more than a year. It's still a good idea, however, to have a written agreement for business transactions beyond an ordinary sale of goods. There is no law requiring a lawyer to write your contract. If the transaction is relatively simple, the contract can also be simple. But you also have to pay attention to certain details to avoid issues arising later.
Describe the payment terms for the transaction, including the total amount for the service, how much and when the deposit is due and how much and when the final payment is due. Spell out a time line or milestones. Include specific dates for the delivery of parts of the service or the final deadline for the service to be complete.