A certificate of payment is a document issued during construction projects certifying that a contractor has completed specified work and is entitled to receive payment. Typically prepared by the project's architect or engineer, the certificate confirms that work completed matches contract requirements before the owner releases funds. Progress payments are made throughout construction as work milestones are reached, rather than in a single payment at completion. The certification process protects owners by ensuring they only pay for satisfactory work while providing contractors with regular cash flow. Municipal construction projects follow formal certification processes to ensure proper use of public funds.