Reformation of a Written Instrument as a Cause of Action in New York

Reformation is a legal claim that allows a party to ask the court to correct a written agreement so that it reflects what the parties actually intended. It does not create a new contract but instead corrects an existing one that, due to a mistake or fraud, fails to match the original agreement. In New York, the courts are cautious when asked to rewrite contracts and will only do so if specific legal requirements are met.

The Parties Had a Clear Agreement or Understanding

The first requirement for reformation is that the parties reached a clear agreement before putting anything in writing. This means both sides understood and agreed to the same terms. There must be evidence that this understanding existed, such as emails, notes, or consistent testimony. Without proof that the parties actually agreed on specific terms, there is nothing for the court to correct.

For example, imagine two businesses agree that a piece of equipment will be delivered on June 1, but the contract mistakenly says July 1. If both parties had clearly agreed to the June date, that is the kind of mistake reformation is designed to fix.

A Mistake Occurred When Reducing the Agreement to Writing

The second element is that the mistake happened while writing down the agreement. This mistake can be one of two types: a mutual mistake, where both parties are unaware that the written document contains an error, or a one-sided mistake combined with fraud, where one party makes an honest mistake and the other party intentionally takes advantage of it.

In the earlier example, if both parties believed the contract said June 1 but later discovered it said July 1, that would be a mutual mistake. If one party knew about the error and intentionally stayed silent to gain an advantage, that could support a reformation claim based on fraud and mistake.

The Written Contract Does Not Reflect the Original Agreement

The final requirement is that the contract, as written, includes or omits terms that were not part of the original understanding. The mistake must be significant enough to make the written agreement unfair or misleading. The goal of reformation is to align the document with what the parties actually intended—not to fix a bad deal or add new terms that were never discussed.

Conclusion

Reformation of a written instrument is a powerful legal tool that corrects errors in contracts when those errors do not reflect the true intentions of the parties. In New York, a party seeking reformation must prove that there was a clear agreement, that a mistake occurred when writing it down, and that the written version includes or omits terms that do not match the actual deal. This cause of action ensures that contracts are not only legally binding but also truthful representations of what both sides agreed to.

Find the Law

“In order to obtain reformation of a written instrument it must be shown that “the parties came to an understanding, but in reducing it to writing, through mutual mistake, or through mistake on one side and fraud on the other, omitted some provision agreed upon, or inserted one not agreed upon.” William P. Pahl Equipment Corp. v. Kassis, 182 A.D.2d 22, 29 (N.Y. App. Div. 1992)