Texas Property Code - PROP § 13.001. Validity of Unrecorded Instrument

(a) A conveyance of real property or an interest in real property or a mortgage or deed of trust is void as to a creditor or to a subsequent purchaser for a valuable consideration without notice unless the instrument has been acknowledged, sworn to, or proved and filed for record as required by law.

(b) The unrecorded instrument is binding on a party to the instrument, on the party's heirs, and on a subsequent purchaser who does not pay a valuable consideration or who has notice of the instrument.

(c) This section does not apply to a financing statement, a security agreement filed as a financing statement, or a continuation statement filed for record under the Business & Commerce Code.