Conductiio Indebiti

Conductio Indebiti is a form of Unjustified Enrichment. It involves where an enrichment is received through performance of obligation with "isn't due".

What isn't due?
Examples of an "undue" obligation are:
 * Overpayment of a debt, or payment of a non existing debt
 * Where a payment is to the wrong person
 * Payment of a void contract

Steps to determining

 * 1) A benefit must be conferred by one person, and received by another
 * 2) The purpose must be to discharge a duty recognised in law
 * 3) The purpose must have failed - and failed because it was not due.
 * 4) The reason why the benefit was conferred must be due to an error about legal liability.

Additiionally, the recovery must be equitable, and there must be no relevant defence.

An example of this is in Morgan Guaranty Trust Co of New York vs Lothian Regional Council. Morgan Guaranty had made payments to Lothian Regional Council under what both parties thought was a valid contract, when this was revealed not to be the case, Morgan sought the return of this money. As there was no question as to whether return was equitable, the money was ordered returned.

The error that lead to to the undue payment can be a mistake in fact, or law. However the nature of the mistake, and if it is an excusable one, can have an effect on whether the resolution is equitable.