You Can’t Just Say ‘I Didn’t Know What I Signed’

The Supreme Court recently shed important light on the rarely successful legal plea of non est factum – a Latin phrase. Simply put, it’s a claim that someone signed a legal document without understanding what they were signing, and therefore, should not be bound by it. The Court said this doctrine is available only in very limited situations under contract law.

The Supreme Court clarified that to rely on non est factum, a person must show that they were fundamentally mistaken about the nature of the document they signed—believing it to be something entirely different. Crucially, this mistake must have been caused by deception or misleading conduct by another party. It is not enough to simply say, “I didn’t read it.” The law expects people to take reasonable care before signing legal documents.

The Supreme Court made it very clear that the burden of proof lies on the person who raises the plea. That means the person claiming they didn’t know what they were signing must prove two things:

1. That the document signed was radically different from what they believed they were signing, and
2. That they were not negligent—that is, they weren’t careless in failing to read or understand the document.

What Happened in the Case?

This case involved a business partnership between two parties dating back to 1992. At that time, one partner signed several legal documents, including one marked as “V1.” Later, the signer claimed he didn’t understand the documents and didn’t know what he had agreed to. He said he was deceived into signing and therefore should not be bound by them.

The case first went before the District Court, which ruled in favor of the person claiming deception. The High Court (Civil Appellate) agreed with the District Court and dismissed the defendant’s position without thoroughly examining whether the claim of deception was actually supported by evidence.

The Supreme Court took a very different view. It carefully examined the claim through the lens of the legal principle of non est factum. It emphasized that this defense can only succeed in very rare cases—typically involving people who are blind, illiterate, or suffering from a disability that prevents them from understanding what they are signing.

In this case, the person raising the plea was of full mental and physical capacity. The Supreme Court found that he had failed to prove that the document he signed was radically different from what he intended to sign, or that he had been tricked or deceived in any specific way. It also noted that he had not taken enough care before signing the documents, and no concrete evidence of fraud was presented.

“…it is clear that the plea of non est factum is extremely narrow in its application. With the Plaintiff neither being blind nor illiterate, in order to succeed with the plea, he was required to satisfy the following: 

(1) That he was under a fundamental misapprehension as to the nature of the document that was signed with such document being radically different from the one the Plaintiff intended to sign, as a result of being misled or induced by deception practiced on him; 

(2) The Plaintiff must not have been negligent. 

It is hard to envisage of a case where a person of full capacity would be able to succeed with the plea, for the reason that if someone has taken reasonable care to ascertain what he was signing, it would be most unusual if he does not realise what the document actually is…” 

–Justice Arjuna Obesekere

The Supreme Court was critical of both the District Court and the High Court, saying they had accepted the plaintiff’s version too easily without examining whether it was backed by evidence. It found that there had been no proper basis to conclude fraud or deception, and the findings were flawed. As a result, the Supreme Court set aside both lower court judgments.

However, the Supreme Court also noted that a sum of Rs. 134,644, which had been with the defendant since 1992, rightly belonged to the plaintiff. Allowing the appeal without returning this money would unjustly enrich the defendant. Therefore, while dismissing the action, the Court ordered the money to be returned to the plaintiff.

“the District Court disregarded that evidence on the basis that the Plaintiff was old and did not know what he was doing. While the age of the Plaintiff is admitted, the evidence of the Plaintiff does not support a finding that the Plaintiff did not have sufficient understanding as to what he was doing when he read and signed V1 in 1992. The law is very clear on this point. A person who has read the impugned document cannot later claim that his mind did not align with his hand. Commerce cannot work if a person is allowed to resile from his acts so easily.”  – Justice Arjuna Obesekere

Case No: SC Appeal No. 08/2014 [Decided on 30.05.2025]

Before: E.A.G.R. Amarasekera, J Yasantha Kodagoda, PC, J Arjuna Obeyesekere, J