How do I defend a claim from my contractor?

Start with the clock. Across Australia, state security of payment law sets a short deadline for a payment schedule, and missing it can make you liable for the full claim. For example, under Queensland's BIF Act 2017 it is due within 15 business days of the claim, or sooner if the contract says so.

Go item by item. For each, say whether it is in scope, instructed, notified in time and priced fairly. Give reasons.

Gather your own proof: instructions you gave, programme updates, site records and any contractor delays. A counterclaim needs the same care as a claim.

Consider independent help early. A timeline and a cost review can turn a large claim into a short list of real issues.