The short answer
Unjust enrichment allows recovery when one party retains a benefit at another’s expense in a way that would be unfair, and no enforceable contract covers the situation.
Where it fits in your case
Often pleaded as an alternative when the existence or scope of a contract is disputed.
What to expect
No express contract. If a valid contract governs the subject, unjust enrichment generally is not available.
Alternative pleading is allowed when a contract’s existence is disputed.
Measure. Recovery focuses on the value of the benefit conferred.
What we need from you
Evidence of the benefit provided, its value, and the other side’s knowledge and retention of it.
Common misconceptions
“It’s a backup to any contract claim.” Not if a valid contract covers it.
“It recovers our lost profits.” It measures the benefit to the other side.