Closing the final account

Under AS 4000 and AS 2124 the final account is where the whole commercial story of the job is reconciled to a single number. It takes the contract sum, adds and subtracts every variation, adjusts for remeasured work and provisional items, accounts for retention, and produces the final amount due. Done well it is arithmetic. Done late it is a negotiation nobody enjoys.

What the final account gathers

• The contract sum. The starting figure, before any change.
• Variations. Every directed variation at its agreed value, and any that remain in dispute clearly flagged.
• Remeasurement. Provisional quantities and schedule-of-rates work adjusted to the quantity actually built.
• Retention. The full release position, both tranches accounted for.
• Any claims. Extension of time cost, delay costs and other entitlements, settled or reserved.

Build it as you go

The final account is not an event at the end of the job. It is the cumulative progress claim, agreed. Every month the claim values work, prices variations, and moves retention. If those figures were agreed as they arose, the final account is the last claim with the retention released. If they were parked, the final account becomes the moment a year of parked disagreements arrives at once.

It is still a payment claim

The final claim is a payment claim under the Security of Payment Act like every claim before it. The respondent answers with a payment schedule on the state business-day clock, and an unanswered final claim carries the same consequence as any other. Agreeing the account by negotiation is preferable, but the statutory route stays open if the schedule never comes.

GST on the closing figure

The final account is reconciled net, and GST of ten per cent applies to the taxable balance actually falling due. Because retention release is itself a taxable supply, the closing GST has to follow the net movements rather than being applied to a gross final figure.

Close it, do not leave it

An open final account ties up retention, working capital and management attention long after the site has gone. The discipline that closes it is unglamorous: agree each variation when it happens, remeasure as the work completes, and diary the retention dates. Then the final account is a signature, not a fight.