The Offer to Purchase is the first legally binding contract in a Massachusetts real estate transaction. Whether you are a Buyer or Seller, it is critical to understand that this document sets the foundation for your future Purchase and Sale Agreement—and ultimately, your closing. This document contains all of the material terms of the transaction including the parties, purchase price, deposit amount, inspection contingencies, mortgage contingencies, what is included and not included and additional important terms. Once signed by both parties, it becomes legally enforceable, and any mistakes made here can have long-term consequences.