How do i contact nationstar mortgage customer service? You can call Nationstar Mortgage at (469) 549-2000 phone number, write an email, or write a letter to Nationstar Mortgage LLC, PO Box 650783, Dallas, Texas, 75261-9741, United States. Nationstar Mortgage Customer Service Phone Number (888) 480-2432, Email, AddressWho is nationstar mortgage llc in texas? Nationstar Mortgage LLC. Nationstar Mortgage LLC, doing business as Mr. Cooper, offers mortgage services. The Company provides mortgages loan, re-financing, and home equity loans. Mr. Cooper serves client in the state of Texas.What is the case number fornationstar mortgage llc? Nationstar Mortgage LLC., Case No. 16-cv-01335, filed in the Superior Court of California, County of Santa Cruz. The Law Office of Balam O. Letona, Inc., represents the homeowners. Comments are closed.What is the rating of nationstar mortgage? Overall Rating: 4.2 / 5 (Average) With over 2.9 million customers, Nationstar Mortgage is one of the largest non-bank lenders in the United States.