What is the effect of starting to perform in a bilateral contract?

• A. Starting performance is an acceptance and creates an implied promise to finish the job.
• B. Starting performance revokes the offer.
• C. Starting performance creates a separate option contract.
• D. Starting performance has no effect.

Answer: (A)

Starting to perform when an offer invites performance acts as acceptance and carries an implied promise to finish. When you begin the work in response to an offer, your actions signal that you have accepted the terms and are bound to complete the rest of the performance. That completion obligation is the implied promise: by starting, you’ve shown you intend to be bound and will finish the task as agreed, with the other party obligated to pay upon completion. This explains why starting work has a binding effect, rather than revoking the offer or creating a separate option contract, and why it isn’t a null or meaningless act. For example, if a contractor offers to pay for painting the house and says to start now, beginning the painting acceptance commits you to finish, and stopping mid-project could amount to breach.