The proposal includes the work to be completed and the price. An accepted and signed business proposal is not a contract if the signature was appended for discussion purposes.Each proposal must include a response to each item in the RFP in the order given. The document becomes a binding contract only when one party finally signs an unconditional acceptance of the other side's proposal. Buyers: Withdrawing an Offer. Most contractors will allow you to withdraw if they have not started work because they figure if you feel like that, you will be a problem customer.