The client walks the site and says, “While you’re here, can you move that wall and add another power point?” You say yes, because you want to keep them happy and the job moving. Three weeks later the final invoice lands, the client disputes the extra charge, and you have nothing in writing. If that sounds familiar, you are not alone, and it is exactly where QBCC contract variations catch out good tradies.
It is frustrating. You did the extra work in good faith, and now the paperwork feels like it is working against you. This guide walks through what the QBCC actually requires for variations to a domestic building contract, so you can protect your payment and your licence without slowing the job down.
Why QBCC contract variations matter more than you think
A variation is simply a change to the contract after it has been signed. That could be a different tile, an extra window, a revised floor plan or a delay caused by something unexpected. The QBCC advises keeping variations to a minimum, because every change adds cost, time and risk of a dispute.
The catch is that for domestic building work, variations are regulated. A written contract is required for any domestic building work priced over $3,300 (including labour, materials and GST), and it must be in writing, signed and dated by both parties, and comply with Schedule 1B of the QBCC Act. Not using a compliant contract is an offence, and the QBCC can issue fines, prosecute, take disciplinary action or apply demerit points. The variation rules sit on top of that foundation.
Many contractors we speak to say the same thing: “The client agreed, so why does it matter that it is not on paper?” It matters because the QBCC does not assess what was said on site. It assesses what was documented.
What a compliant variation must include
According to the QBCC, you must present the variation to the home owner in writing, and the owner must agree to it in writing before the variation work starts. The document needs to be easy to read and must contain:
- A description of the variation
- The date the variation was requested
- Your reasonable estimate of any resulting delay
- The change to the contract price, or how that change is calculated
- When any price increase is payable, or when any decrease will be credited
- Any change to home warranty cover that the variation triggers
Notice what is missing from that list: vague wording like “extras as discussed”. A variation that does not clearly describe the work and the price is a variation waiting to become an argument.
The timing rules that trip up busy builders
Timing is where most mistakes happen. The QBCC says you must give the owner a written copy of the variation before the variation work starts, or within 5 business days of both parties agreeing to it, whichever comes first. The only exception is urgent work where producing a written copy first is genuinely not practicable.
There is also a payment rule worth tattooing on the dashboard: you cannot require payment for a variation before the variation work has started. Asking for a variation deposit up front, even a small one, puts you on the wrong side of the rules.
Here is a simple process that keeps you compliant without drowning in admin:
- Pause at the request. When a client asks for a change on site, say “Happy to price that, I will send it through today.”
- Write it up the same day. Use a variation template with the five required elements above.
- Deliver it properly. In person, by post, by email or as your contract’s notice provisions allow, and keep proof of delivery.
- Get the owner’s written agreement. Do not start the variation work until you have it.
- File it with the contract. Store the signed variation alongside the original so an audit or dispute is a five-minute job.
If you have already done work without a written variation
If you are reading this with a stack of undocumented extras behind you, take a breath. This is common, and it is fixable if you act before it becomes a complaint. The longer an undocumented variation sits, the harder it is to prove what was agreed, and the more likely a client is to raise it with the QBCC.
Start by collecting whatever evidence exists: emails, text messages, photos of the changed work and any updated plans. Then check how your current contract handles changes, because an out-of-date, interstate or self-drafted contract can itself breach Queensland requirements. The QBCC itself recommends getting legal advice before relying on a self-drafted domestic contract.
If your paperwork is a mess and you are worried about a licence audit, a disputed invoice or demerit points, you do not have to sort it out alone. Our team helps contractors tidy up their documentation and get compliant before a problem escalates. Book a Strategy Session and we will map out the fastest way to fix it.
Choosing the right contract for the job size
Variations are only as strong as the contract underneath them. The QBCC sets different contract types depending on the price of the work:
- $3,300 or less: the Small building projects contract can be used. It is illegal to use it for work priced above $3,300.
- $3,301 to $19,999: a Level 1 renovation, extension and repair contract, with a signed, dated copy to the owner within 5 business days of entering the contract.
- $20,000 or more: a Level 2 contract. The QBCC consumer building guide must be given before the owner signs, the signed contract provided within 5 business days, and a commencement notice within 10 business days of work starting on site.
The classic trap is a job that starts under $3,300 and grows through variations. Once the total price passes the threshold, the small-job contract is no longer the right document. Check the running total every time you add a variation, not just at the start.
Make variations a habit, not a headache
Written variations feel like extra work in the moment, but they are the cheapest insurance you can buy. They protect your payment, give the client clarity, and show the QBCC that you run a professional operation. A one-page template and a same-day rule will cover most jobs.
Do not wait for a complaint to find the gaps. If you want help getting your contracts and variation process audit-ready, book a Strategy Session with QBCC Express today and fix it while it is still easy.
Frequently Asked Questions
Do QBCC contract variations have to be in writing?
Yes, for domestic building contracts. The builder must present the variation to the owner in writing, and the owner must agree to it in writing before the variation work starts. Verbal agreements on site do not meet this requirement.
How long do I have to give the owner a written copy of a variation?
You must provide the written copy before the variation work starts, or within 5 business days of both parties agreeing, whichever comes first. The only exception is urgent work where a written copy first is not reasonably practicable.
Can I ask for payment before starting variation work?
No. The QBCC states you cannot require payment for a variation before the variation work has started. Plan your invoicing so any variation payment follows the start of that work.
What must a written variation document contain?
It must describe the variation, state the date it was requested, give your reasonable estimate of any delay, state the price change or how it is calculated, and state when a price increase is payable or a decrease credited. It should also be easy to read.
When is a written domestic building contract required in Queensland?
A written contract is required for domestic building work priced over $3,300, including labour, materials and GST. It must be signed and dated by both parties and comply with Schedule 1B of the QBCC Act.
