Build the claim,
line by line to the total.

It depends on how the contract is written, and the two produce different cash figures on the same claim, which is why the calculator asks instead of choosing for you. Where retention is treated as a reduction in the amount claimed, GST is calculated on the reduced figure. Where the full value is invoiced and retention is deducted from the payment afterwards, GST is calculated on the full value. Both appear in practice. Read the payment clause, pick the option that matches it, and confirm the GST treatment for your contracts with your accountant against current ATO guidance. This page is general information, not tax advice.

More than the number this calculator produces. A claim that gets approved without a fight identifies the parties and the contract, carries its own number and date, names the stage exactly as the claim schedule names it, itemises each approved variation with a reference to the signed paperwork, shows the GST position and states the total and the due date. Behind it sits the evidence pack, dated photos, any inspection record marking the stage boundary and the variation approvals. The full working list is on the progress claim checklist, which is built to be run against a live claim.

Usually with the stage they belong to, itemised on their own lines rather than absorbed into the stage amount. Claiming them together keeps one document per period and one approval conversation, and it lets the client reconcile the total against the contract without a phone call. Itemising them separately within that document is what stops an approved variation being mistaken for an inflated stage claim. What is never worth doing is holding variations back to claim at the end. Variations left off claims are revenue delivered and unbilled, and they are one of the most common causes of a job that felt profitable finishing thin.

Not automatically, and keeping them distinct is the cleaner practice. The claim is made under the contract and usually passes through the client's approval. The tax invoice is the accounting document raised once the claim is approved, and on most residential jobs it is what starts the payment terms running. Every day between approval and invoice is a day added to the payment cycle for nothing. The relationship between the two, and the timing consequences, are set out in the progress claims reference.

Enter the contract sum including approved variations and the total previously claimed, and the calculator returns the position after this claim along with the balance still to come. It is worth checking every period rather than at the end, because the two ways it goes wrong are both quiet. Claiming ahead of the work is a dispute waiting for someone to notice, and claiming behind the work is an interest-free loan to the client that nobody records. If the remaining balance goes negative, the claims have exceeded the contract sum and something needs reconciling before the claim goes out.

The claim value goes negative, which is a real situation rather than an error. It happens when a period is dominated by a provisional sum adjustment in the client's favour, an agreed back charge or a credit note. The calculator withholds no retention on a negative claim, because withholding a percentage of a credit makes no sense. How a negative period is actually presented, as a credit note or as an offset against the next claim, is a contract and accounting question worth settling with your accountant before it arises rather than during it.

Yes. On a stage-based contract you enter the stage amount from the claim schedule as the work completed this period. On a percentage-of-completion contract you enter the value completed during the period, which is the value complete to date less the amount already claimed. Either way the field means the same thing, the value being claimed for this period, and the arithmetic below it is identical. The two claim structures, and which suits which kind of job, are covered in the progress claims reference.