Legal Definitions - special non est factum

Special non est factum refers to a specific and stringent legal defense known as non est factum, which is Latin for "it is not my deed." This defense allows a person to argue that a document they signed should not be legally binding on them because they were fundamentally mistaken about its true nature or character at the time of signing, and they were not negligent in making that mistake.

The term "special" emphasizes that the circumstances must be particularly compelling and meet a high legal threshold for the defense to succeed. It is not a separate defense, but rather highlights the strict conditions under which a non est factum claim can be successfully made. For this defense to apply, two main conditions must be met:

• Fundamental Mistake: The person must have been mistaken about the type or character of the document they were signing, not merely its terms or contents. They must have believed it was something entirely different from what it actually was.
• Lack of Negligence: The person must not have been careless or negligent in signing the document. This often applies when the signer is illiterate, blind, mentally incapacitated, or was misled by fraud or misrepresentation by another party, and took reasonable steps (given their circumstances) to understand the document.

Here are some examples illustrating how this defense might apply:

• Example 1: Elderly Individual with Visual Impairment and Deception

  Mrs. Henderson, an 85-year-old woman with severe cataracts and limited literacy, is visited by a door-to-door salesperson. The salesperson presents her with a document, telling her it's a simple entry form for a free prize draw. Trusting the salesperson, and unable to read the small print, Mrs. Henderson signs where indicated. Unbeknownst to her, the document was actually a contract for a high-interest loan secured against her home.

  How it illustrates the term: Mrs. Henderson could potentially invoke the defense of special non est factum. She made a fundamental mistake about the character of the document, believing it to be a prize draw entry rather than a loan agreement. Crucially, given her severe visual impairment and limited literacy, she was not negligent in signing without fully understanding the contents, especially since she was actively misled by the salesperson.

• Example 2: Individual with Cognitive Impairment and Misrepresentation

  Mr. Davies, an adult with a diagnosed intellectual disability that significantly impairs his ability to understand complex financial transactions, is approached by a distant relative. The relative asks Mr. Davies to sign a document, explaining it's just a formality to help them open a joint bank account for household expenses. In reality, the document is a guarantee for a substantial business loan taken out solely by the relative, making Mr. Davies liable for the debt.

  How it illustrates the term: Mr. Davies could argue special non est factum. He fundamentally misunderstood the nature of the document, believing it to be a simple administrative form for a joint account, not a personal guarantee for a large loan. Due to his cognitive impairment and the misrepresentation by the relative, he was not negligent in signing the document without fully grasping its true legal implications.

• Example 3: Non-English Speaker and Fraudulent Contract

  Ms. Chen, a recent immigrant who speaks very little English, visits a car dealership. She agrees to purchase a car and is presented with a stack of documents to sign. The salesperson points to various lines, telling her these are standard purchase agreements and registration forms. Ms. Chen signs them, trusting the salesperson. One of the documents, however, was a separate, highly unfavorable service contract for an extended warranty she never discussed or agreed to, with a very high, non-refundable fee.

  How it illustrates the term: Ms. Chen might successfully claim special non est factum regarding the extended warranty contract. She believed she was signing documents related solely to the car purchase and registration. Her fundamental mistake about the character of the warranty contract, combined with her significant language barrier and the salesperson's misrepresentation, could demonstrate that she was not negligent in signing a document she could not understand.