Ever wrapped up a job, sent the invoice, and then thought… “Hang on, where’d the profit go?”
You’re not alone. A lot of tradies quote a job, smash through the work, collect payment, and only later realise they’ve undercooked it. Labour took longer, materials blew out, or the apprentice clocked more hours than expected.
By then, it’s too late. The job’s done, the bill’s been paid, and your margin’s disappeared.
That’s where back costing comes in.
What is back costing?
Back costing is simply comparing what you estimated a job would cost with what it actually cost once it’s finished.
Sounds straightforward, right? But here’s the kicker: most tradies don’t really do it, or if they do, it’s with messy spreadsheets, scraps of paper, or in a meeting with their accountant at the end of the financial year.
The problem? By then, the lessons are already lost. You don’t know which stage of the job blew out. You don’t know if it was labour, materials, or a subbie. You can’t fix your quoting for next time.
Why the old way doesn’t work
Here’s how it usually plays out:
- You quote the job, maybe with a bit of gut feel built in.
- The crew gets on with it. Timesheets are scribbled on paper or texted through.
- You buy materials as you go, keep the receipts in the ute or crumpled in the glove box.
- At the end, you invoice what you quoted, maybe whack on a few extras if you remembered to note them.
And that’s it. Job done.
The problem? You never get the full picture. You don’t know if that deck actually made you money. You don’t know if the bathroom reno took 20 hours more than you thought. And you definitely don’t know if your crew cost you more than you charged the client.
That’s not running a business — that’s guessing.
Back costing the right way (and why it matters)
Done properly, back costing shows you exactly where your profit is coming from and where it’s leaking out.
- Labour: How many hours did the crew actually put in? Were they on the money, or did it blow out?
- Materials: Did prices change? Did you underestimate the quantity? Did you get stung on delivery?
- Other Costs: Subbies, fuel, equipment hire, waste removal — all the extras that sneak in.
With that info, you can:
- Quote smarter next time (no more undercutting yourself).
- Spot which types of jobs make the most money.
- Have the backup to push back on a client who reckons you’ve overcharged.
- Build a business that actually grows, instead of one that’s always chasing its tail.
How NextMinute makes it simple
Here’s the bit most other job management tools miss: NextMinute lets you track labour, materials, and other costs by job and job stage.
Not just “the job as a whole.” You can see:
- How much the framing stage cost in time and materials.
- Whether the tiling stage came in under or over.
- If that landscaping project blew out on labour but stayed tight on supplies.
And because it’s all in real time, you don’t wait until the job’s finished to know the damage. You can see where you’re at as you go — and make changes before it’s too late.
That’s a massive difference. Instead of looking back in regret, you’re steering the job while it’s happening.
Plus, at the end, you’ve got proper reports showing actuals vs estimates, and your profit margin by job and job stage. That’s gold when it comes to quoting the next job, because you’re working off real numbers, not gut feel.
Why it matters now more than ever
Let’s be real: materials aren’t getting any cheaper, labour shortages are biting, and clients are more cost-sensitive than ever. One wrong quote can wipe out the profit on a month’s worth of work.
Back costing isn’t just good practice. It’s survival. The tradies who know their numbers win more jobs, keep their margins, and grow. The ones who don’t are the ones still scratching their heads come tax time.
Ready to stop guessing?
If you’re running on gut feel and scraps of paper, you’re flying blind. Back costing with NextMinute gives you control. You’ll know which jobs make you money, which don’t, and how to sharpen your quoting so you’re never working for free again.
👉 Book a chat to see how NextMinute’s back costing works for Aussie tradies.
Check out our recent webinar showing how to quote and back cost in NextMinute:
