The way that contractors usually get paid for their completed work, is determined by the size of the job and the contract agreement. In large jobs they can be paid through interim certificates that the Contract Administrator issues after a valuation, occurring at specific intervals. This would account for the percentage of work completed against the overall task and materials used to realise this task.

The frequency of the valuations and subsequently the issuing of interim certificated depends on the initial agreement between the client and the contractor and the duration of the project. For projects that run for months or even years, interim certificates are normally issued once a month. The client is obliged to then pay for the full value of the interim certificate, unless he requests for a Payless Notice to be issued explaining to the Contract Administrator why that should be the case.