The contractor hourly invoice is a demand for payment delivered to a client by a contractor who has performed services for them. An invoice can be used to bill a client after a certain period of time (for example, on a bi-weekly or monthly basis) or after all tasks have been completed by the contractor. A description of the services and the cost per service will be outlined in the invoice. Furthermore, any materials or products that were purchased by the contractor will be billed to the client. The total amount owed plus additional taxes and the date by which payment must be made by the client will be included at the bottom of the document.