Unwritten law is the law not promulgated and recorded, as mentioned in Section 1896, but which is, nevertheless, observed and administered in the Courts of the country. It has no certain repository, but is collected from the reports of the decisions of the Courts, and the treatises of learned men.
§ 1899.“Unwritten law” defined
Title 2. Of the Kinds and Degrees of Evidence · Chapter 3. Writings · Article 2. Public Writings · Enacted 1872 · no amendments on record · Last verified July 29, 2026
In one sentenceSection 1899 defines unwritten law as law that is not promulgated and recorded within the meaning of Section 1896, yet is still observed and administered in the courts, with no fixed repository, drawn instead from court decisions and legal commentary.
Full Text of § 1899
Plain-English Summary
This section completes the pair begun in Section 1896 by defining the other half of the written/unwritten division. Unwritten law is law not promulgated and recorded in the sense Section 1896 describes, but it is still observed and administered in the courts of the state, meaning it carries genuine legal force despite lacking a single official text.
Because it has no certain repository, unwritten law has to be gathered from sources that record it indirectly: the reports of court decisions and the writings of legal scholars and commentators. That makes proving unwritten law a different exercise than proving a statute, since there is no single official document to point to.
Frequently Asked Questions
What is unwritten law under this section?
Law that is not promulgated and recorded as Section 1896 describes, but that is nevertheless observed and administered in the courts.
Where is unwritten law found if it has no official written text?
It is collected from the reports of court decisions and from the writings of legal scholars, since it has no certain repository.
How does unwritten law differ from a statute?
A statute is promulgated in writing with an existing record; unwritten law carries legal force without ever having been promulgated and recorded that way.
Amendment History
(Enacted in 1872.)
Source & verification. Section text is reproduced verbatim from
the West's Annotated California Codes / Thomson Reuters. Enacted by the California Legislature.
Last verified July 29, 2026.
· Official source
Also known as: definition of unwritten law californiacommon law versus statutory law source