As the Editor suggested, a written Offer to Purchase is a binding contract in Massachusetts if certain conditions are met, such as acceptance of the offer by the seller, intent of the parties to be bound by the offer, and inclusion of material terms in the offer. Many standard offer forms will include language such as "this is a legal document that creates binding obligations." Additionally, most offers will contain many of the provisions of a P&S agreement, such as inspection and mortgage contingencies, that will merge into the P&S. If you are nearing the deadline of the tax credit, your attorney should include clear language that, once the offer is accepted, the buyer and seller are entering in a binding contract. Even better, I would suggest that instead of "Offer", your attorney should title your initial contract with the seller a "Contract for Sale of Real Property," and include many of the provisions later found in the P&S.