Texas Estates Code - EST § 751.134. Effect on Certain Persons of Termination of Durable Power of Attorney or Agent's Authority

Termination of an agent's authority or of a durable power of attorney is not effective as to the agent or another person who, without actual knowledge of the termination, acts in good faith under or in reliance on the power of attorney.  An act performed as described by this section, unless otherwise invalid or unenforceable, binds the principal and the principal's successors in interest.