Certificate of completion construction

This computes the money on a certificate of completion. Enter the contract sum, the agreed variations, the retention percentage, what has been paid to date, the defects liability period and the share of the retention released at completion, and the page returns the final account, the retention held over the contract, the retention released now, the amount held until the end of the defects period, the sum due on this certificate and the defects period itself. A certificate is a document with a number the client has to pay; this is that number, shown.

The final account is the contract plus what was agreed, not what was done

Work done outside the scope without an agreed variation is not in the final account, however real it was. The page adds the agreed variations, positive or negative, to the contract sum, because that is the figure the certificate can be enforced on. The daily log and the change record are where the disputed work lives until it is agreed.

Retention is released in two halves, on two dates

The common shape is half the retention released at practical completion and the other half at the end of the defects liability period, after the snag list is closed. The page splits it at the share you set and prints the amount held until the defects period ends, which is the figure to chase on the date it falls due.

Due now is what gets paid, so put it last and put it big

A certificate that ends in the final account, a retention line and a total, with the payments to date somewhere in the middle, gets queried. One that ends in a single sum due, after the payments to date and the retention still held have come off, gets paid. The page computes it that way for that reason.