Alteration Law and Legal Definition

Alteration generally means modification or change.

Alter is defined as "to cause to become different in some particular characteristic . . . without changing into something else." United States v. Kilbride, 2009 U.S. App. LEXIS 23722 (9th Cir. Ariz. Oct. 28, 2009)

With regard to property, it refers to substantial change to real estate especially to the structure. This does not involve an addition to or removal of the exterior dimensions of a building’s structural parts. In order to constitute alteration, the changes made should be substantial.

With regard to instruments,it refers to any act done to an instrument, after its execution, whereby its meaning or language is changed; especially, the changing of a term in a negotiable instrument without the consent of all parties to it. Generally, material alterations make an instrument void.

An alteration is material:

  • if it changes the burden of a party like changing the date, time, place, amount or rate of interest.
  • If it changes the liabilities or duties of any party like adding or removing the name of a maker, drawer, indorser, payee or co surety
  • If it changes the operation of the instrument or its effect in evidence like changing the form of an indorsement, or changing liability from joint to several.