Head Contractor Disputing Your Hours or Scope? How to Fight Back

You submitted your invoice for $18,000. The head contractor paid you $12,000 and says the rest is “backcharges” for defective work you never did. Or they are claiming you only worked 120 hours when your timesheets show 160. Or they added extra scope and now refuse to pay for it because “it was included.”

Common dispute tactics builders use

• Backcharges — deducting money for alleged defects, clean-up, or rework without evidence or proper notice
• Hour disputes — rejecting timesheets or claiming fewer hours were worked
• Scope creep denial — asking for extra work verbally then refusing to pay because “it was in the original quote”
• Delay deductions — blaming you for project delays caused by their poor scheduling
• Retention withholding — holding 5-10% retention and never releasing it
• Set-off claims — claiming you owe them money for site access, safety equipment, or materials

How to fight each one

Backcharges

Most subcontractor agreements require the builder to give you written notice of defects and a reasonable opportunity to rectify before they can backcharge. That rule comes from your subcontract, not the Security of Payment Act, so check its defects clause. If they just deducted the money without the notice your subcontract requires, the backcharge is likely invalid.

Hour disputes

Keep your own timesheets, signed daily if possible. Photos with timestamps on site are strong evidence. Text messages confirming hours or tasks are admissible.

Scope disputes

Every variation should be in writing — but even a text message saying “can you also do the downpipes?” followed by “yep, $800” is a written variation. Screenshot everything.

Serve a payment claim

If the builder is withholding payment, serve a payment claim under your state’s Security of Payment Act. Outside the Northern Territory, the builder must answer with a payment schedule within the time the Act allows (in NSW, 10 business days) or becomes liable for the full amount claimed.

Start your claim today

Claim Done drafts your Payment Claim for $49. Tell us the situation — disputed hours, invalid backcharges, unpaid variations — and we draft a payment claim under your state’s Security of Payment Act. Sent to the builder. Done in about 5 minutes.