“Mistakes on tax returns can prove costly. What was your biggest tax time mistake?”

I don’t think I’ve made any huge tax-time mistakes. I’m fanatical (my wife says “anal”) about filing receipts.

When I started my first full-time job, I hadn’t done my returns for the last few years of uni. Through either laziness or, um … let’s go with laziness, I asked a mate for a recommendation. And that’s how I met Dale.

Dale’s advice was to “just throw everything in a shoebox, Bruce, and we’ll sort it out once a year”. Simple, like a Kojak haircut.

Nowadays I’m an investor and a small business owner, so that system has grown to literally eight shoeboxes and 20 lever-arch folders. Getting good advice and a system early in life has made me tens of thousands of dollars.

Two tips. Get yourself both an accountant who knows your industry and a shoebox.

But we’re talking my mistakes.

My biggest mistake would be not checking over Dale’s work thoroughly enough some years. Dale has made me thousands, but nobody knows your personal finances like you do and professionals sometimes err.

For three years running, a major property deduction was missed. But it wasn’t anything a few amended tax returns couldn’t fix.

The lesson? Hiring professionals doesn’t absolve you from checking. It’s your money.

I also wish I’d learned more earlier about tax and investments. It’s not what profit you make, it’s what you get to keep that determines your success as an investor.

Bruce Brammall is the author of Debt Man Walking (www.debtman.com.au) and a licensed financial adviser.