Texas Civil Practice and Remedies Code - CIV PRAC & REM § 63.003. Effect of Service

(a) After service of a writ of garnishment, the garnishee may not deliver any effects or pay any debt to the defendant.  If the garnishee is a corporation or joint-stock company, the garnishee may not permit or recognize a sale or transfer of shares or an interest alleged to be owned by the defendant.

(b) A payment, delivery, sale, or transfer made in violation of Subsection (a) is void as to the amount of the debt, effects, shares, or interest necessary to satisfy the plaintiff's demand.