The builder's losses are not your debt

Treat every deduction as separate

A builder who runs over budget may try to turn the pain into back-charges, defect claims or withheld money. That does not mean the whole loss belongs to you. Start by treating each deduction as a separate claim, not a warning to accept a smaller cheque just to keep the job moving or approve more work today. ([business.gov.au](https://business.gov.au/people/contractors/laws-affecting-contracts?utm_source=openai))

The practical risk is simple: if you let one unexplained deduction stand, the next one becomes easier to repeat. A short written response, sent early, keeps the issue commercial. Ask for the basis of the charge, the exact work said to be defective, and the money trail behind every amount while the trail is fresh. ([business.gov.au](https://business.gov.au/people/contractors/laws-affecting-contracts?utm_source=openai))

Make the builder prove it

Before you argue, make the builder prove the deduction. Ask for itemised backup: labour hours, plant charges, supplier invoices, photos, rectification quotes and the contract clause relied on. If they say the problem came from your trade, ask them to identify the date, instruction and evidence, not just the conclusion or invoice date cited. ([business.gov.au](https://business.gov.au/people/contractors/prepare-a-contract?trk=article-ssr-frontend-pulse_little-text-block&utm_source=openai))

Keep your own file just as tight. Save site instructions, day sheets, emails, texts, variation approvals and progress claims in date order. When the builder starts mixing defects with delay and cost overrun, your record should show what was actually instructed, what changed, and what was billed each time for each part of the job. ([business.gov.au](https://business.gov.au/people/contractors/prepare-a-contract?trk=article-ssr-frontend-pulse_little-text-block&utm_source=openai))

Source: Official guidance

Keep your payment rights alive

Do not stop lodging payment claims because the project has gone sour. Security of payment laws in each state and territory set timeframes for payment claims and, in most places, a path to adjudication if the claim is ignored. Missing your own deadline can weaken your position even when the builder owes you money before any response window closes. ([business.gov.au](https://business.gov.au/planning/industry-information/construction-industry?utm_source=openai))

If the contract calls for a response within a set time, respond within that time. Say which deductions you dispute, which parts you accept, and what documents are missing. A calm partial response is better than silence, because it preserves your objection while showing you are still dealing with the account professionally and keeping the matter ready for later review by an adviser. ([business.gov.au](https://business.gov.au/people/contractors/prepare-a-contract?utm_source=openai))

Put changes in writing

From now on, keep every instruction in writing. Business.gov.au advises that contract changes can be made verbally, but it is better to put them in writing and have both parties sign. On a troubled job, that paper trail helps separate genuine variations from after-the-fact blame shifting and delay claims for variations and back-charges alike. ([business.gov.au](https://business.gov.au/people/contractors/prepare-a-contract?trk=article-ssr-frontend-pulse_little-text-block&utm_source=openai))

If the builder says the extra cost came from your mistake, ask them to connect it to a dated instruction, a signed variation or a specific breach. Do not rely on site talk. A written reply forces everyone to deal with the same facts, not the loudest version of the story before the next payment date. ([business.gov.au](https://business.gov.au/people/contractors/prepare-a-contract?trk=article-ssr-frontend-pulse_little-text-block&utm_source=openai))

Respond fast, then escalate

The best time to challenge a deduction is before the account hardens into a stalemate. Send one letter or email that asks for itemised evidence, confirms the amount you dispute, notes any payment claim still being pursued, and asks for a written response by the contract deadline and attach the supporting evidence. ([business.gov.au](https://business.gov.au/people/contractors/laws-affecting-contracts?utm_source=openai))

If you are already juggling deductions, variations and a strained payment schedule, bring the papers together now and get a second set of eyes on the dispute. CRP can help you work through dispute resolution steps with independent qualified professionals. This is general information only, not legal advice, and your contract may need tailored advice before the next move. ([business.gov.au](https://business.gov.au/people/contractors/prepare-a-contract?trk=article-ssr-frontend-pulse_little-text-block&utm_source=openai))