Amendment means a formal revision or any addition proposed or made to a statute, Constitution, pleading, order or other instrument. The change can be made by addition or deletion or correction.
Under Criminal law generally information can be amended at any time before the verdict or finding provided it does not prejudicially affect the rights of the defendant.
Example of a piece of Federal Legislation on amendment of information
USCS Fed Rules Crim Proc R 7
(e) Amending Information. Unless an additional or different offense is charged or a substantial right of the defendant is prejudiced, the court may permit information to be amended at any time before the verdict or finding.
Example of a State Statute on amendment of information
22 Okl. St. § 304 Information may be amended
An information may be amended in matter of substance or form at any time before the defendant pleads, without leave, and may be amended after plea on order of the court where the same can be done without material prejudice to the right of the defendant; no amendment shall cause any delay of the trial, unless for good cause shown by affidavit.