Uncodified means a principle is not written in legislative laws or statutes, but rather, exists only by virtue of the common law. That is, uncodified refers to practices or rules that exist solely through judicial decisions.
For example, one of the most basic requirements in a criminal trial is that a defendant has the presumption of innocence and the prosecution must prove the defendant’s guilt. The presumption of innocence is not explicitly stated in the Constitution or in any federal statutes, but the Supreme Court has ruled on its requirement. Furthermore, uncodified can sometimes be used in a wider sense to refer to principles that are entirely unwritten.
[Last updated in June of 2024 by the Wex Definitions Team]