I want to write a letter that is compelling. My realtor says he's not allowed to attach letters to offers because he can lose his license.Focus on three things: State your intentions, show that you have the financial means to make the purchase and make a personal appeal to the seller. Address the Seller and Introduce Yourself. Make your opener as personal as possible. Here are house offer letter samples to win a bidding war. 3 examples to use as a reference point. Your letter should explain why you're interested in buying the house and include details regarding your mortgage financing and expected closing date. Make sure the price is right. We're talking about how to write an offer to purchase a home all right so how do you structure your offer to make sure that the seller accepts it.