What are the Risks of not having a written contract?

When a contract is not in writing, you are exposing yourself and/or your business to a number of risks:

The risk that you or the other party misunderstood an important part of the agreement, such as how much was to be paid for the job or what work was to be carried out
The risk that you will have a dispute with the other party over what was agreed because you are both relying on memory
The risk that a court won’t enforce the contract because you may not be able to prove the existence of the contract or its terms.