Bookkeeper for Builders Sydney | Job Costing, Progress Claims and Variations (2026)

You approved fourteen variations on the Mosman job. The client said yes to all of them on site, half of them by text. Nine made it onto an invoice. The other five are sitting in your foreman's phone, and the cost of them is sitting in your margin. Boring Barry has no idea, because Barry has every job you've ever built coded to one account called "Building Income". A proper bookkeeper for builders in Sydney would have caught it at the next claim.

Published: November 2026

What does a builder's bookkeeper actually do?

The standard work is the same as any business with staff: bank reconciliation, supplier bills, payroll, BAS. What changes for a custom home builder is that every dollar has to be tied to a job.

Costs coded to the project and the stage they belong to
Progress claims raised against the contract schedule, not from memory
Variations logged when approved and invoiced at the next claim
Deposits held as a liability until the work is done
Retentions tracked until they are released
Subcontractor payments recorded with ABNs for the annual report to the ATO

All of it sits on top of monthly bookkeeping in Sydney, reconciled weekly.

This page is for residential builders running a handful of high-value projects at once. For commercial work and larger subcontract packages, see our construction bookkeeper Sydney page. If you are a trade business, trades bookkeeper Sydney is the better fit.

Job costing: the only report that matters

A builder's P&L for the whole company tells you almost nothing. Three jobs can be quietly losing money while a fourth carries the lot, and the total still looks fine. You find out when the fourth one finishes.

Job costing fixes that. Every supplier bill, every subbie invoice and every hour of site labour is coded to a project in Xero, and ideally to a stage within it: site works, slab, frame, lock-up, fit-out, completion. Then each job has its own running P&L against the budget you priced it on.

Barry does not do job costing. Barry does a shoebox, annually, and describes the result as "old-school integrity".

Worked example: where five variations went

Illustrative figures only, all ex GST.

A Sydney builder signs a custom home at a contract value of $2,400,000, priced on a cost budget of $2,040,000.

Planned margin: $2,400,000 − $2,040,000 = $360,000, or 15% of the contract

During the build, the client approves fourteen variations. Nine are invoiced. Five are done, paid for and never billed.

Cost of the five unbilled variations: $65,000
Margin if nothing else changes: $360,000 − $65,000 = $295,000
As a share of the contract: $295,000 ÷ $2,400,000 = 12.3%

Almost three points of margin gone, on one house, with no cost overrun at all. The work was done properly and the client was happy to pay. Nobody sent the invoice.

With job costing in place, the variance shows up in the month the cost lands: the job is running over budget on a stage, someone asks why, and the answer is "variation 11, not billed yet". It goes on the next claim.

Progress claims: bill the contract, not the bank balance

Residential contracts set out when you can claim: usually a deposit, then stages through to practical completion. A bookkeeper who understands building keeps a schedule for each job showing every stage, its value, whether it has been claimed and whether it has been paid.

Three things go wrong without that schedule:

A stage is reached and nobody raises the claim for a fortnight
A claim is raised for the wrong amount because the variation register wasn't checked
A claim is paid short and nobody notices, because the receipt was coded to "sales" and not matched to the invoice

Each of those is your money, late. For anything about your rights under the contract or what you can claim and when, talk to your lawyer or industry association. The bookkeeping job is to make sure every claim you are entitled to raise goes out on the day, for the right amount, and gets chased.

Deposits and retentions

Deposits. A deposit taken before work starts is not income yet. It is the client's money sitting with you against work to come, and it belongs on the balance sheet until the first stage is done. Booked as income on day one, it inflates the month you signed and leaves a hole later.

Retentions. Where a contract lets the client hold back part of each claim until the defects period ends, that money is still owed to you. It needs its own account, by job, with the release date. Otherwise it gets forgotten, and money you have already earned never gets asked for.

Subbies, suppliers and the 28 August report

A custom home runs on subcontractors and trade accounts, and both need to be paid in a rhythm that matches your claims. Pay everyone the day the bill arrives and you fund the job yourself. Pay late and your best tiler stops answering.

Our bookkeeper to manage supplier payments service schedules supplier and subbie payments against the cash you actually have and the claims you are about to receive, then prepares the payment batch for you to approve.

There is also a reporting job attached.

Rule: The ATO says a business that is primarily in building and construction and pays contractors for building and construction services must lodge a taxable payments annual report by 28 August each year. A business is treated as primarily in building and construction if 50% or more of its income or its activity relates to those services.

Bookkeeper's job: record every subcontractor payment with the contractor's ABN and the total paid, all year, so the report is produced from the file in August without ringing forty subbies. Our TPAR explained guide covers who lodges and what goes in it.

Site staff and Payday Super

If you employ carpenters, labourers, supervisors or office staff, the ATO's Payday Super rules apply from 1 July 2026. Super guarantee contributions must be received by each employee's fund within 7 business days after payday, with a longer period in limited cases such as new employees. The ATO's super guarantee rate table shows the rate at 12% for 2026-27.

For a crew paid weekly, that is a super deadline every week. It gets paid with the pay run, and site wages are coded to the job they were worked on so labour shows up in the job cost.

Whether someone on site is an employee or a contractor is a legal question with real consequences. Get advice on it. Don't let your bookkeeper guess.

Where Sydney builders' files go wrong

The pattern is the same from Mosman to Castle Hill. Perfect from the street, and behind the hoarding a set of books so stiff they still use carbon paper.

All jobs coded to one income account and one "materials" account
No variation register, or one that lives in a notebook in the ute
Deposits booked as income on signing
Retentions with no account and no release dates
Insurance and certification costs for a specific job sitting in general overheads
Subbie payments recorded without ABNs
A monthly report that shows the company, never the job

That last one is the tell. If your reports can't answer "which job made money", you are flying on instinct. Our monthly reports from your bookkeeper show profit by job, in plain English.

A monthly close for a custom home builder

Reconcile every bank account, credit card and trade account statement.
Code every supplier bill and subbie invoice to a job and stage.
Update each job's claim schedule: stages reached, claimed, paid.
Check the variation register against invoices raised and flag anything approved but unbilled.
Review deposits held and retentions outstanding by job.
Run payroll, pay super with the pay run and code site wages to jobs.
Prepare the supplier and subbie payment batch for approval.
Send the owners profit by job against budget, aged receivables and what is due out this month.

How to tell if you need a new bookkeeper

Ask your current one for two things: the margin on each open job as at last month, and a list of approved variations not yet invoiced. If the answer is silence, a long pause or "I'd have to look into that", you have your answer.

A Free Xero Roast opens the file with your permission, finds the worst five things and puts them on one page. If you are weighing up cost first, see construction bookkeeper cost in Sydney.

FAQ

What does a bookkeeper for builders do differently from a general bookkeeper?

They tie every cost and every invoice to a job. That means job costing by project and stage, a claim schedule for each contract, a variation register checked at every claim, and deposits and retentions tracked on the balance sheet.

How should a building deposit be recorded?

As a liability when it is received, because the work has not been done yet. It moves to income as the related stage is completed and claimed.

How do I stop variations going unbilled?

Keep one register per job, record each variation when the client approves it, and have the register checked against invoices before every progress claim goes out. Job costing gives a second safety net, because an unbilled variation shows up as a stage running over budget.

Do builders have to lodge a taxable payments annual report?

The ATO says businesses primarily in building and construction that pay contractors for building and construction services must lodge one by 28 August each year. A business is primarily in the industry if 50% or more of its income or activity relates to those services. Check the ATO's guidance for your situation.

How does Payday Super affect a building company?

From 1 July 2026, super must be received by each employee's fund within 7 business days after payday, with a longer period in limited cases such as new employees. For crews paid weekly, super is paid weekly.

Can you set up job costing in Xero for jobs already underway?

Yes. Open jobs are set up as projects or tracking categories, costs and claims to date are allocated back to them, and new transactions are coded by job from then on. Finished jobs are usually left as they are.

How much does a bookkeeper for a Sydney builder cost?

It depends on the number of jobs running, the volume of supplier and subbie invoices, payroll size and how much cleanup is needed first. Fixed monthly pricing gives you the figure before the month starts. An hourly bookkeeper at $80 to $150 an hour with no agreed scope usually costs more once job costing is done properly.

Can I switch bookkeepers in the middle of a build?

Yes. The handover covers Xero access, bank feeds, payroll and the claim and variation records for each open job. Our guide on how to change your Sydney bookkeeper sets out the steps.

About Sydney Bookkeeper

Sydney Bookkeeper is the modern, fixed-price Sydney bookkeeper for businesses with staff that are tired of slow, hourly, jargon-spouting incumbents. We work with professional services firms, construction and property businesses, agencies, tech and ecommerce companies, hospitality groups, and health practices across Sydney. Monthly bookkeeping, BAS lodgement, payroll, and Xero file cleanups, all on fixed monthly pricing, no lock-in.

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The team uses a registered BAS Agent for all BAS and IAS lodgement services. Full registration details, agent particulars, and copies of the Tax Practitioners Board (TPB) Code of Professional Conduct, the TPB complaints process, and any conditions on the agent's registration are available on request by emailing hello@sydneybookkeeper.com. This content is general information only, written for Australian small and mid-market businesses. It does not constitute tax, financial product, or legal advice and should not be relied on as such. Tax obligations depend on your individual circumstances. For advice specific to your business, contact the team directly or consult a registered tax agent or licensed financial adviser. Sydney Bookkeeper is not a licensed tax agent or licensed financial adviser. Information was current at the time of publication and may change without notice. We review and update guides periodically.

Sources

Australian Taxation Office, TPAR: building and construction services: https://www.ato.gov.au/Business/Reports-and-returns/Taxable-payments-annual-report/Work-out-if-you-need-to-lodge-a-TPAR/building-and-construction-services/
Australian Taxation Office, How Payday Super works: https://www.ato.gov.au/businesses-and-organisations/super-for-employers/about-payday-super
Australian Taxation Office, Super guarantee rates (2026-27): https://www.ato.gov.au/tax-rates-and-codes/key-superannuation-rates-and-thresholds/super-guarantee