Retention
A percentage of each payment withheld by the employer as security for performance and defects — commonly 5–10% of contract value, released in halves at completion and at the end of the defects liability period.
Retention is the employer’s security and the contractor’s working capital, and those are the same money. It sits, unpaid, on the contractor’s balance sheet for the length of the defects liability period — which can be a year or more after the work is finished and the crew has moved on.
The systemic problem is that it is frequently never released. Not through dispute, but through inattention: the DLP expires, nobody applies, the employer does not volunteer, and the sum quietly ages into a bad debt. A retention ledger with release dates against every contract is the entire remedy, and most contractors do not have one.