I do a lot of probate law, and one thing I often have to "fix" for new clients has to do with the timing of putting the decedent's house on the market. Too often I will get a call saying, "Dad died and we put his house on the Multiple Listing Service. We accepted an offer and we're at the title company, but they're telling me they need some kind of letter before I can sell the house. I don't want to lose the sale, can you write me a letter?"
Well, no - no, I can't. See, the "letter" the title company is talking about is what the Court gives to the executor or administrator of an estate, called "letters testamentary" or "letters of administration". This is basically the Court telling the world that you're entitled to deal on behalf of the estate of the deceased person. Until you have those "letters", you don't have the right to sell your dad's (or whoever the decedent is) property. And until you probate the will (or do an heirship and administration if the person didn't have a will), the Court won't grant those letters. And even an experienced real estate agent might not know that.
Just like the bank not talking to you about your decedent's accounts or the insurance company not answering your emails about who the beneficiary of the life insurance was, the title company won't let you sell your dad's house until they see you have the authority to do so. So hold your horses! Doing things the right way, at the right time, will make handling your loved one's property and estate much easier and less stressful.
As always, the above is legal information and not legal advice, and it's based on Texas law because I'm a Texas lawyer. If you need to probate the estate of a loved one, please contact an experienced probate attorney in your area.