Subcontractor Management for Australian Builders: Compliance, Scheduling, and Not Losing Your Best Subs

If you've been building for more than a year, you know the truth: your business runs on your subs. A reliable concretor, a fast framer, a plumber who actually shows up when they say they will. These relationships take years to build and one bad experience to lose.

The challenge isn't finding subs. It's managing 15 to 30 of them across multiple active projects without something falling through the cracks. A missed insurance renewal. A scheduling conflict. An invoice that sat in your inbox for three weeks.

This guide covers how to build systems that keep your subs compliant, on schedule, and loyal to your jobs.

The Compliance Baseline (This Isn't Optional)

Before a subcontractor sets foot on your site, you need to verify the following. This isn't best practice. It's legal obligation.

Insurance

• Public liability insurance. Minimum $10 million is standard for residential construction. Some principal contractors and clients require $20 million. Check the policy covers the specific work being done on your site.
• Workers compensation insurance. Required in every state if the sub has employees. In NSW, this is managed through icare. In Victoria, WorkSafe Victoria. In Queensland, WorkCover Queensland. Sole traders without employees may be exempt. The rules vary by state.

If a sub's insurance lapses while they're working on your site and someone gets hurt, you have a problem. Not a small one.

Licences and Registrations

Check the sub holds the correct licence for their trade and that it's current:

• NSW: Search the NSW Fair Trading licence register
• VIC: Check the Victorian Building Authority (now Building and Plumbing Commission) register
• QLD: Search the QBCC licence register

Verify the licence class covers the work they'll be doing. A plumber licensed for above-ground work isn't necessarily licensed for below-ground drainage.

Sham Contracting

This is the compliance risk most builders underestimate. The Fair Work Act 2009 makes it illegal to disguise an employment relationship as a contracting arrangement. If a "sub" works exclusively for you, uses your tools, follows your schedule, and can't subcontract their own work. They might actually be an employee in the eyes of the law.

The penalties are significant. The ATO also takes sham contracting seriously from a tax perspective.

How to stay safe:

• Ensure subs have their own ABN and insurance
• Written subcontract agreements for every engagement
• Subs should be free to work for other builders
• Subs provide their own tools and equipment where practical
• Payment is per-job or per-milestone, not hourly

WHS Obligations

Under the model Work Health and Safety (WHS) Act, the principal contractor has duties to subcontractors on site, not just their own employees. This includes:

• Site-specific WHS inductions before work starts
• Providing a safe working environment
• Maintaining a WHS management plan for the site
• Reporting notifiable incidents to the relevant state regulator

Document your inductions. Keep records. If a WorkSafe inspector visits your site, "we do inductions verbally" isn't going to cut it.

Scheduling Across Multiple Builds

Share the program early

Don't call your sub the week before you need them. As soon as you have a project program, share the estimated start dates for each trade. Even if the dates shift (they will), early visibility lets subs plan their own workload.

When you have 8 active projects, your framer might be on 3 of them. If you don't give them forward visibility, they'll take other work during the window you needed them. Then you're scrambling.

Build buffer between dependent trades

Every experienced builder knows this, but it's worth repeating: schedule 1-2 days of buffer between sequential trades. Framing finishes Tuesday, plumber starts Thursday, not Wednesday. That buffer absorbs the inevitable small delays without cascading your entire program.

Communicate changes immediately

When the slab pour gets pushed back a week, every subsequent trade is affected. Notify them the day you know, not the day before they were supposed to start. "Sorry, we're a week behind" is manageable on Monday. It's a relationship-damaging surprise on the day.

Paperless lets you manage supplier and subcontractor relationships within each project: scheduling, documents, and communication tied to the specific build. See how project coordination works.

Written Scope for Every Job (Yes, Even Your Regulars)

"He knows what he's doing, he's done 50 jobs for me" is not a scope document. When something goes wrong, and on a long enough timeline, something will. You need written agreement on:

• What's included and what isn't. "Plumbing rough-in" means different things to different plumbers. Spell it out.
• Who supplies materials? If the sub provides materials, what quality standard? If you do, when will they be on site?
• Timeline and duration. Not just start date, but expected duration. If a five-day job takes ten, you need the conversation documented.
• Clean-up responsibility. Whose job is it to remove waste? Clean the work area?
• Defect rectification. What's the process if their work doesn't pass inspection?
• Payment terms. Amount, milestones if applicable, and due date.

A one-page scope agreement takes 10 minutes to prepare. A dispute over ambiguous scope takes weeks.

Pay Them on Time

This is the simplest retention strategy in construction and the one most often ignored.

Your best subs are in demand. They can choose whose jobs they prioritise. And the number one factor, above loyalty, above convenience, above how nice you are, is whether you pay on time.

The Security of Payment Act (which exists in every Australian state under slightly different names) gives subcontractors the right to pursue payment through adjudication if you don't pay. But no sub wants to go through that process. They'd rather just stop answering your calls and work for the builder who pays in 14 days.

Practical tips:

• Set payment terms in writing before work starts (7, 14, or 30 days from invoice)
• Process invoices the week they're received, not when you get around to it
• If you can't pay on time, tell them before the due date, not after they've chased you twice
• Track payments against the agreed schedule so nothing slips through

One System, Not Five

The builders who manage subs well aren't doing anything magical. They just have their information in one place instead of scattered across:

• Phone contacts for details
• A spreadsheet for insurance dates
• Email for invoices
• WhatsApp for scheduling
• Paper files for scope agreements

When it's all in one platform (sub details, insurance certificates with expiry tracking, project allocation, scope documents, invoices, and communication), nothing falls through the cracks because there are no cracks to fall through.

Get your subcontractor management sorted. Start a free 30-day trial and set up your sub database alongside your first project.