Pre-existing Duty

In one sentence

An obligation a party already has that cannot serve as new consideration.

Plain English

If you are already legally required to do something, doing that same thing again does not count as consideration for a new contract. For example, if a police officer is already paid to investigate crimes, they cannot use that duty as consideration to get extra pay for investigating a specific crime. The pre-existing duty rule prevents people from getting paid twice for the same obligation.

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Example

A construction company agrees to build a house for $200,000. Midway through, they demand an extra $50,000 or they will stop working. The company's pre-existing duty to finish the house (from the original contract) cannot serve as consideration for the extra payment, so the demand is not enforceable.

Used in a sentence

“The employee's pre-existing duty to work her scheduled hours meant her agreement to work those same hours could not be new consideration for a raise.”

Related terms

Consideration

Something of value exchanged by each party to make a contract binding.

Contract

A legally binding agreement between two or more parties to do or not do something.

Illusory Promise

A promise that appears binding but actually gives one party the power to escape it.

Breach of Contract

Failure to do what a contract requires, without a valid legal excuse.

Waiver

Voluntarily giving up a legal right you're entitled to.

Offer

A proposal to enter into a binding agreement on specific terms.

Acceptance

Agreeing to the exact terms of an offer, creating a binding contract.

Offeror

The person who makes an offer to enter into a contract.

This page is a plain-English reference and is not legal advice. Laws vary by jurisdiction and change over time. For specific situations consult a licensed attorney.