Paying subcontractors correctly: the invoicing and TPAR workflow

Most subcontractor disputes on residential sites in NSW do not start with a badly drafted subcontract. They start with the gap between the invoice arriving and the money leaving. Somebody measures the work, somebody else approves the claim, the accounts person pays whoever is named on the invoice, and the record that survives is a bank transfer with a reference number that means nothing six months later.

That gap is where builders lose money. It is also where the taxable payments annual report, usually called the TPAR, becomes painful, because the report is only as good as the payment records underneath it. If the invoice was issued by a different entity than the one that signed the subcontract, or if a cash payment was made to keep a subbie on site, the annual report will not reconcile and the correction falls on you.

This article is about the workflow itself: how a subcontractor invoice should move from claim to payment to record, what the security of payment framework requires of you along the way, and how the TPAR obligation sits on top of it. It does not cover the commercial terms of the subcontract, which are dealt with in the article on subcontract agreements for builders, and it does not cover deadlines, which are covered in the article on TPAR due dates.

Why the payment workflow matters more than the contract

A subcontract sets out the deal. The payment workflow is what actually happens. When a matter ends up in adjudication or in front of a certifier, the documents that decide it are almost never the signed subcontract alone. They are the invoice, the payment schedule, the remittance, and the site diary that shows what was done and when.

That is why the workflow deserves as much attention as the contract. A builder who has a reasonable subcontract and a disciplined payment process will usually be able to resolve a dispute because the paper trail is consistent. A builder with an excellent subcontract and a chaotic payment process will often lose, not because the contract was wrong, but because nobody can prove what was agreed and what was paid.

The workflow also drives your own margin. Every payment that is coded to the wrong job, or approved on a verbal estimate rather than a measurement, is a cost that will not show up until the project is finished and the margin has already gone. Catching it at the point of approval is cheap. Catching it at practical completion is not.

The subcontractor invoice is a claim, not a bill

There is a useful distinction here that many builders blur. A trade supplier sends you a bill for goods delivered. A subcontractor sends you a claim for work done. The claim is a statement that a defined scope has reached a defined point, and it should be assessable against something you already hold: the subcontract, the schedule of rates, or the scope of works attached to the purchase order.

If the invoice does not reference the subcontract or purchase order and the claim period, it cannot be properly assessed. The correct response is not to pay it and sort it out later. The correct response is to send it back and ask for a claim that can be measured. That is not pedantry; it is the difference between a payment you can defend and a payment you cannot.

The claim should also identify the legal entity that is claiming. In residential building it is common for a subbie to trade through a company but quote under a personal name, or to have a trading name that does not match the ABN on the invoice. If you pay the wrong entity, you have not discharged your obligation under the subcontract, and you have created a tax record that will not match the annual report.

Assessing the claim before you approve it

Approval is the point where the money is committed, so it should be the point where the most scrutiny happens. The person approving should be able to answer three questions: is the work in the claim actually complete, is it acceptable, and is the claimed value consistent with how the subcontract says it will be valued?

On a residential site the practical version of this is a short walk with the claim in hand. The supervisor marks off the items claimed, notes anything incomplete or defective, and records the percentage or stage that has genuinely been reached. That note is the evidence that supports the approval, and it is the document that protects the builder if the subcontractor later disputes the assessment.

Where the claim includes variations, the approval should confirm the variation was authorised before the work was done. A variation approved after the fact is a commercial concession, not a contractual entitlement, and paying it without authorisation weakens your position on every future variation on the same project.

Retention, set-off and what you can lawfully withhold

Builders withhold money for three different reasons, and they are not interchangeable. The first is retention, which is a contractual right to hold a percentage of each progress payment until a defined point, usually practical completion or the end of the defects liability period. The second is a set-off or back-charge for defective work, damage, or costs the builder has had to cover. The third is simply withholding payment because the builder is unhappy about something.

The first two are legitimate if the subcontract allows them and if they are documented. The third is where builders get into trouble. Under the security of payment framework in NSW, a subcontractor has a statutory entitlement to progress payments and a process to recover them. If you receive a payment claim and do not respond with a payment schedule within the time the Act allows, you can lose the right to raise defences later. The dispute stops being about whether the work was worth the money and becomes about whether you followed the process.

That is the commercial reality. Withholding payment as leverage feels like strength, but it usually converts a commercial argument into a statutory debt claim, and it damages your position in any adjudication. If you have a genuine set-off, document it, quantify it, and apply it through the payment schedule rather than by simply not paying. The NSW Government’s guidance on security of payment for construction contractors sets out how the scheme operates and what a payment schedule needs to do.

Paying the right entity to the right account

Once a claim is approved, the payment itself should be mechanical. The amount approved goes to the entity named in the subcontract, into the account nominated by that entity, with a remittance that states the invoice number and the period covered. Nothing about that should be improvised on the day.

There are two common failures here. The first is paying a different entity because the invoice came from a related company or a trust. The second is paying into a different account because the subcontractor asked for it by text message. Both create risk. The first creates a tax and contract mismatch. The second creates a payment fraud risk that has become common enough in construction that it is worth a written rule: account changes are confirmed by a phone call to a known number, not by email alone.

Cash payments deserve a specific mention. They are legitimate in some circumstances but they are the hardest to record correctly and the easiest to get wrong in the annual report. If a payment is made in cash, the record still has to identify the payee, the ABN, the amount and the period. If it does not, you have created an unreconcilable item in your own file.

How the TPAR sits on top of your payment records

The taxable payments annual report is the ATO’s mechanism for matching payments in the building and construction industry to the contractors who received them. If you are a business that makes payments to contractors for building and construction services, you may need to lodge a TPAR. The ATO’s guidance on building and construction services for TPAR sets out who is covered and what counts as a reportable payment.

The important point for the payment workflow is that the TPAR is not a separate exercise you do at year end. It is a summary of records you either kept or did not keep during the year. If your payment file for each subcontractor identifies the legal entity, the ABN, the total paid and the GST, the report is a retrieval exercise. If it does not, the report becomes a reconstruction, and reconstructions are where errors and penalties live.

That is why the invoice check at the start of the workflow matters so much. A payment recorded against the wrong ABN in July is a correction in August, and by then the subcontractor may have changed entities, deregistered, or simply stopped answering the phone. The cost of fixing it is real, and it lands on the builder because the reporting obligation is the builder’s, not the subcontractor’s.

There is also a broader reform context worth being aware of. The Australian Government’s 2026–27 Budget tax reform measures include changes to how payments to contractors are treated for reporting purposes, which is a reminder that the direction of travel is toward more, not less, matching of payments to entities. Builders who already keep clean payment records will absorb those changes as a configuration exercise. Builders who do not will absorb them as a compliance project.

What good looks like: a payment file per subcontractor

The single most useful change a builder can make is to stop filing subcontractor paperwork by job and start filing it by subcontractor, with a cross-reference to the job. The job file tells you what the project cost. The subcontractor file tells you who you paid, under what contract, for what claim, and when.

That file should contain the subcontract and any variations, the insurances and licences you collected before they started, every invoice and progress claim, the approval note, the payment schedule where one was issued, the remittance advice, and the payment record. It is a thin file, but it answers almost every question that arises later, whether from the subcontractor, an adjudicator, a certifier, or the tax office.

It also makes the annual reporting straightforward. When the TPAR is prepared, the total for each subcontractor is the sum of the payment records in that file, and the ABN is the one on the subcontract. There is no guessing, and no exposure to the situation where a payment cannot be attributed to anyone.

Worked example: a builder in western Sydney

A builder in western Sydney is running a project with a framing subcontractor, a bricklayer, and a tiler. The framing subcontractor invoices monthly, the bricklayer invoices at completion of each stage, and the tiler invoices at the end. The builder’s office manager pays each invoice as it arrives, codes all of them to the job, and files them in the job folder.

At year end, the builder’s accountant asks for the TPAR information. The framing invoices are clean and reconcile to the subcontract. The bricklayer’s invoices are issued by a company, but the subcontract was signed by the individual, and the payments were made to the individual’s account. The tiler’s final invoice includes a variation that was never authorised in writing, and the builder paid it because the tiler was needed on the next project.

None of these are unusual. All of them are fixable at the point of payment and expensive at the point of reporting. The bricklayer’s mismatch requires the builder to establish who the correct payee was and to correct the record, and it raises the question of whether the subcontract should have been with the company in the first place. The tiler’s unauthorised variation is now a precedent, and the next variation on the next project will be harder to refuse.

The fix is not complicated. Before the first payment, the builder confirms the entity and the ABN against the subcontract and records them in the subcontractor file. Every payment is made to that entity. Every variation is authorised in writing before the work is done. Every payment goes into the subcontractor file as well as the job file. The workflow takes a few minutes per claim and removes the year-end problem entirely.

Where the security of payment framework changes the workflow

The security of payment framework is the reason the payment workflow cannot be treated as a purely internal accounting process. It gives subcontractors a statutory right to progress payments and a process to enforce them, and it imposes obligations on the builder at each step, particularly around responding to a payment claim.

In practice, this means the builder needs to know when a claim has been received, what the subcontract says about the claim period and the response time, and what the Act requires. The response is not optional, and it is not the same as a phone call saying the claim is being looked at. If you are not sure what your obligations are on a particular claim, that is the moment to get advice, not after the response period has passed.

For builders doing their continuing professional development, the security of payment framework and the payment workflow sit alongside contract administration and business compliance. The guide to how NSW builder CPD works explains how those categories fit together, and the course catalogue lists the modules that cover them in more detail.

The commercial reality of getting it wrong

Most builders understand the contractual risk of a payment dispute. Fewer price in the administrative cost. A single mismatched payment can take hours to correct, and if it cannot be corrected it can expose the builder to a reporting penalty and an amended assessment. A pattern of mismatches across a year can turn the annual reporting exercise into a project that consumes the first quarter of the new financial year.

The reputational cost is harder to quantify but just as real. Subcontractors talk to each other. A builder who pays on time, pays the right entity, and issues a remittance without being chased is a builder subbies want to work for. That matters when trades are tight, and it matters more than a slightly cheaper rate from someone who is slow to pay.

The workflow described here is not bureaucratic. It is the minimum discipline required to keep the contract file, the tax file and the site file saying the same thing. Builders who do it find that disputes are rarer, reporting is simpler, and their own margins are more visible. Builders who do not find out at the worst possible time, usually when a subcontractor has stopped work and the certifier is asking questions. More resources on the business side of building are available through the PointCPD home page for NSW builder CPD.

Questions builders ask

• Bookkeeping
• Contracts
• Subcontractors
• Tax

Published 14 September 2026. General information for builders, not legal, financial or engineering advice for a specific job. Check current requirements with the relevant regulator or standard before relying on them.