Information and belief is a phrase that is normally used in legal pleadings such as complaints and answers during a lawsuit. It is also sometimes used during affidavits under oath, declarations under penalty of perjury. In these instances, the individual stating the phrase or statement qualifies it. Thus, what the individual is really stating is "I am only stating what I have been told, and I believe it."
The purpose of this phrase is to show which statements the individual is sure about and distinguish from statements that the individual is unsure about or lacks personal knowledge (such as if it’s hearsay). The point of stating this phrase is to protect the individual making the statement from claims of perjury or outright falsehood. The typical phrasing of “information and belief” is: "Plaintiff is informed and believes, and upon such information and belief, alleges that defendant diverted the funds to his own use."
See Vertex Inv. Co. v. Schwabacher in which this phrase is specifically used.
[Last updated in June of 2020 by the Wex Definitions Team]