A civil-law concept defining a rule, doctrine, or procedural mechanism used to resolve private disputes. It applies when its legally specified conditions are satisfied and produces defined consequences in adjudication or settlement. It does not apply where required elements or prerequisites are not met. It materially affects rights, obligations, or available remedies in civil controversies. The concept is generally stable, though statutory and doctrinal refinements may occur over time.

Principle

When parties repeatedly perform under a particular contract, their consistent conduct can clarify the meaning of its terms and show the parties' tacit agreements about interpretation and waiver of strict contractual provisions.

Demonstration

A supplier and buyer repeatedly accept late deliveries over several shipments without objection. Courts may treat that pattern of acceptance as a course of performance indicating a mutual tolerance of delayed delivery for that contract.

Misapplication

Treating isolated or one-time acts by a party as a determinative course of performance or using conduct under different contracts to define terms for the present contract misapplies the doctrine.

Consequence

Proper reliance on course of performance promotes pragmatic, contextual interpretation of the contract and can establish implied modifications, waivers, or standards of performance specific to the parties' dealings.

Reversal

The reversal privileges only the written text: no regard is given to how parties actually performed, so ambiguities are resolved solely from the document and extrinsic conduct is disregarded, potentially producing rigid outcomes.

Boundary

Applies only to conduct under the contract being interpreted (not prior separate transactions), requires repeated or consistent acts, and cannot override an unambiguous integrated term unless an established course demonstrates a clear mutual intent to modify.

Semantic Tension

Overlaps with course of dealing and trade usage: course of performance is internal to the contract at hand, while course of dealing concerns prior transactions and trade usage concerns industry practices; courts must sort which contextual source is most probative.

Synthesis

Course of performance is the contemporaneous pattern of conduct under a specific agreement that supplies interpretive weight to ambiguous terms and can evidence agreed practical adjustments or waivers between the contracting parties.