Contractual mistake

A stupid mistake, yesterday.

An area of contract law beloved of university professors and their students.

• Unilateral mistake
• Mutual mistake
• Mistake of law
• Mistake of fact

One thing to be clear: if you make an error what you agree with your counterparty, but your counterparty understands it and agrees it — that’s not a contractual mistake in a legal sense. It's just your screw up, and you’re stuck with it, barring the good graces of a beneign counterparty who might deign to let you out. You did a bad trade, hotshot.

See also

• Counterparts and Confirmations (Section 9(e))in the ISDA master agreement, addressing the question who is the contracting party and what counts as a mistake. Trader is; settlements and confirmations dude in ops isn't.