The first step is the details. Scroll down to the bottom of this section to define the purchase price, offer date, expiration date, and closing date.It is not illegal, in any state of the USA, to write a letter with your offer. Select ONE of the following options as it applies to the method of valuation and the Agency's Approved Procedures. Delete the options that aren't applicable. Address the Seller and Introduce Yourself. When you craft an offer letter, the goal is to help differentiate your offer so you can stand out among potential buyers. Ready to make a real estate offer in Washington DC? Our latest guide has everything you need to know, from pre-approval to negotiating. This is a basic tutorial on writing up an offer for a WA single family home only.