(810 ILCS 5/3-407)
(from Ch. 26, par. 3-407)
(a) "Alteration" means (i) an unauthorized change in an instrument that
purports to modify in any respect the obligation of a party, or (ii) an
unauthorized addition of words or numbers or other change to an incomplete
instrument relating to the obligation of a party.
(b) Except as provided in subsection (c), an alteration fraudulently
made discharges a party whose obligation is affected by the alteration
unless that party assents or is precluded from asserting the alteration.
No other alteration discharges a party, and the instrument may be enforced
according to its original terms.
(c) A payor bank or drawee paying a fraudulently altered instrument or a
person taking it for value, in good faith and without notice of the
alteration, may enforce rights with respect to the instrument (i) according
to its original terms, or (ii) in the case of an incomplete instrument
altered by unauthorized completion, according to its terms as completed.
(Source: P.A. 87-582; 87-1135.)