What Do You Need to Make an Offer on a House? Work with your agent to submit a written offer based on local market value, specifying how and when the steps in the purchase will happen.An offer consists of: 14 Family Contract (or similar contract depending on property type), Seller's Disclosures, MUD Notice, HOA Addendum, Other Addendum. You will write two checks upon the seller accepting your offer. The first will be the Earnest Money. This means you have to take out a mortgage. Use the full legal names of the buyer and seller.