Repeated District Letter Errors on Federal Reserve Notes: When the FRB Prefix Appears Twice in the Serial Number Block
Among the rarest and most visually striking error notes in modern U.S. currency collecting, repeated district letter errors occur when the Federal Reserve Bank prefix letter is inadvertently duplicated within the serial number block. This deep-dive explores how these errors happen, which series and districts produce the most collectible examples, and what collectors should know before adding one to their portfolio.
Read More →