Nemo dat quod non habet

Nemo dat quod non habet, literally meaning "no one [can] give what they don't have" is a legal rule, sometimes called the nemo dat rule that states that the purchase of a possession from someone who has no ownership right to it also denies the purchaser any ownership title. This rule usually stays valid even if the purchaser does not know that the seller has no right to claim ownership of the object of the transaction (bona fide).

This rule is exemplified in circumstances such as the Holocaust reconciliation movement where property, such as works of art, that was stolen or confiscated by the Nazis is returned to the families of the original owners. Anyone who purchased the art or thought they had ownership are denied any rights over the litigious property due to the nemo dat rule.

There are numerous exceptions to the nemo dat rule. Legal tender, for example, does not follow the rule. If a rogue gives cash to someone, that individual will not have to return the bills to the true owner under any circumstances.