Many contractors use a preprinted proposal form that, when signed by the owner, becomes the contract between the parties. This provides a simple way to create a written contract. However, proposals designed as selling tools may lack some important provisions you need to protect your interest in the event of a dispute. To create a proposal form that also makes a safe contract, consider including the following: Price and payment terms. Set a time limit for the owner to accept the price given. Labor and material costs change, and you do not want there to be any question about your obligations should the owner not execute and return the proposal for several months. Generally, contractors require payment in full on completion of work.