Final account in construction

In practice for trades

The final account is where the paperwork of the whole job comes home. It starts from the contract sum, then adds agreed variations, adjusts provisional sums and prime cost sums to their actual cost, adds any loss and expense, and deducts what has already been paid on interim payments. The retention position is dealt with separately as it is released.

Agreeing it is a negotiation, and the party with the better records wins it. Every variation instructed on site and never confirmed in writing is a line you will struggle to recover. Trades routinely lose four figures here, not because the work was not done, but because there is no evidence it was instructed.

Treat the word final seriously. Once you have signed it off, reopening a final account is difficult, so check that late variations, outstanding day works and any claim you intend to make are all in it before you agree the figure.

Worked example

A contract sum of £50,000 with £6,200 of agreed variations, a provisional sum adjusted down by £800, and £47,000 already paid on interim payments. The final account totals £55,400, leaving £8,400 due, less any retention still held.