Real Estate

I was hired by a landowner to help him with the sale of his home. He had listed the property with an agent to no success. The property had been listed for over 6 months. I told him that I would but only as a consultant. I am RE agent licensed in CA but no NM thus wanting to make sure that he would have to be the point person for a FOR SALE BY OWNER sale. I guided the seller to a successful sale. We are now in escrow and no the seller does want to. pay my the agreed upon compensation. I would like to place a lien on the property so that I can make sure that it goes on record during the escrow period. I have over 5 months of correspondence that verify that I worked for the individual and the sale of said home.