A simple form of contract, appropriate when the work scope is not clearly defined. The contractor is remunerated on the basis of labour hours priced at an agreed rate, together with materials used to deliver the service, also priced at an agreed rate. For example, a plumber called out to fix a leaking tap would be on a time and materials contract as the scope of the work cannot easily be ascertained in advance. The work could range from taking five minutes for a simple repair or potentially involve replacing parts or even work to the connecting pipes. The time and materials contract is an efficient method for payment in these situations. See also Remuneration. .