- Retention
- A percentage of each certified bill held back by the client until defined completion or defect-liability events. Tracking it accurately is one of the largest single sources of contractor working capital.
- IPC (interim payment certificate)
- The periodic certificate of work completed that a contractor bills against, typically monthly, with retention and deductions applied before the net payable.
- Variation or extra work
- Work outside the original scope, agreed during execution. Uncertified variations are the most common reason completed work never gets paid for.
- Vendor advance
- Money paid to a supplier or subcontractor before delivery or certification, which must be recovered against later bills. Untracked advances are a silent margin loss.
- Comparative statement
- A side-by-side comparison of vendor quotations used to justify an award decision, and the document an auditor asks for when a purchase is questioned.
- Committed cost
- Cost a project is already obligated to through released purchase orders and subcontracts, whether or not an invoice has been received.