Formal requirements
Wis. Stat. § 405.104
in effectA letter of credit, confirmation, advice, transfer, amendment, or cancellation may be issued in any form that is a record and is authenticated by any of the following methods:
(1) A signature.
(2) In accordance with the agreement of the parties or the standard practice referred to in s. 405.108 (5).
Source: WI Statutes (Official Site)URL: https://docs.legis.wisconsin.gov/document/statutes/405.104Fetched: 10/7/2026