Tex. Business & Commerce Code § 5.104: FORMAL REQUIREMENTS.

A letter of credit, confirmation, advice, transfer, amendment, or cancellation may be issued in any form that is a record and is authenticated:

(1) by a signature; or

(2) in accordance with the agreement of the parties or the standard practice referred to in Section 5.108(e).

Amended by Acts 1999, 76th Leg., ch. 4, Sec. 1, eff. Sept. 1, 1999.