A comprehensive guide to earnest money deposits in Arizona, along with details on requirements, payments, disputes, and refunds. What is Due Diligence when Buying a Home in Phoenix AZ?Due diligence refers to a buyer's investigation of the various aspects of a property. Due diligence within real estate transactions refers to both the buyer and seller satisfying various aspects of a purchase contract before finalizing things. Put down some earnest money to prove you're committed and ready to make this your dream home. The Arizona REALTORS® Residential Resale Purchase Contract Due Diligence Section: Inspection Period and Buyer Disapproval. Typically, you have 10 days to do all of your inspections and investigations of the home. You can inspect anything to do with the home. Earnest money is a deposit the buyer puts down when they're interested in buying a house. Most contracts include a due diligence deadline anywhere from seven days to two weeks after the agreement date.