In contract law, a non-compete clause (often NCC), or covenant not to compete (CNC), is a clause under which one party (usually an employee) agrees not to enter into or start a similar profession or trade in competition against another party (usually the employer). Some courts refer to these as "restrictive covenants." As a contract provision, a CNC is bound by traditional contract requirements including the consideration doctrine.
The use of such clauses is premised on the possibility that upon their termination or resignation, an employee might begin working for a competitor or starting a business, and gain competitive advantage by exploiting confidential information about their former employer's operations or trade secrets, or sensitive information such as customer/client lists, business practices, upcoming products, and marketing plans.
However, an over-broad CNC may prevent an employee from working elsewhere at all. English common law originally held any such constraint to be unenforceable under the public policy doctrine. Contemporary case law permits exceptions, but generally will only enforce CNCs to the extent necessary to protect the employer. Most jurisdictions in which such contracts have been examined by the courts have deemed CNCs to be legally binding so long as the clause contains reasonable limitations as to the geographical area and time period in which an employee of a company may not compete.
The extent to which non-compete clauses are legally allowed varies per jurisdiction. For example, the state of California in the United States invalidates non-compete-clauses for all but equity stakeholders in the sale of business interests.
As far back as Dyer's Case in 1414, English common law chose not to enforce non-compete agreements because of their nature as restraints on trade. That ban remained unchanged until 1621, when a restriction that was limited to a specific geographic location was found to be an enforceable exception to the previously absolute rule. Almost a hundred years later, the exception became the rule with the 1711 watershed case of Mitchel v Reynolds which established the modern framework for the analysis of the enforceability of non-compete agreements.