condition subsequent

a timing relationship that links a contractual obligation to the occurrence of some subsequent event. A condition subsequent refers to a continuing obligation to perform under the terms of a contract pending some event which will then terminate that obligation.

Fergus owns an executive placement firm, specializing in accountants. As part of his contact with each client, he agrees to work to place that client in a suitable position continuously, until such a time as the client is gainfully employed. The client's gainful employment is a condition subsequent that releases Fergus from his contractual obligation to perform his placement activities.