5 Tax Mistakes Costing You Thousands

Running a successful business is no small feat. Between managing staff, growing revenue, and looking after your family, it’s easy to let tax planning slip down the priority list. But overlooking even a few key details can quietly cost your business thousands each year.

At Doyle Accountants, we work with local business owners just like you — people with thriving companies, growing families, and a clear vision for the future. Here are five of the most common tax mistakes we see, and how to avoid them.

1. Poor Business Structure

Many businesses start out as sole traders or partnerships and never revisit whether that structure still suits them. As your business grows, so too does your risk — and the need for better tax efficiency.

The problem: Operating under the wrong structure can mean you’re paying more tax than necessary, missing out on asset protection, or exposing your family home to business risk.

The solution: Review your structure regularly with us. It may be time to consider a company or trust structure that better suits your current size and goals.

2. Failing to Plan for Provisional Tax

If your business is turning a healthy profit, you’re probably paying provisional tax. But many business owners get caught out by underestimating it or forgetting to set funds aside.

The problem: Surprise tax bills, interest, and late payment penalties can bite hard — especially when cash flow is tight.

The solution: Work with us to forecast income and plan for tax payments in advance. A smart tax management plan can smooth out your cash flow and avoid nasty surprises.

3. Not Claiming All Eligible Expenses

We often find business owners missing out on legitimate deductions — either because they don’t realise what they can claim, or because they haven’t kept proper records.

The problem: You end up paying tax on money you didn’t need to, which eats into your profits.

The solution: Keep accurate records, especially for mixed-use expenses like home office costs, vehicles, and travel. Talk to us about what you can legitimately claim — and make sure nothing is left on the table.

4. Mixing Business and Personal Finances

This is a common trap, particularly for owners of growing businesses. You use the company card for personal purchases, or pay for business costs from your personal account.

The problem: This creates messy records, opens you up to audit risk, and makes it harder to claim correct deductions.

The solution: Keep business and personal finances completely separate. Use dedicated business accounts and credit cards, and pay yourself a salary or shareholder drawings instead of dipping into the till.

5. DIY Accounting Without Expert Advice

Software like Xero makes bookkeeping easier, but it can’t replace professional advice — especially when tax laws change or your business reaches the next level.

The problem: Mistakes in GST, PAYE, or income tax can lead to costly corrections, penalties, and lost opportunities for tax savings.

The solution: Get expert support from us who understands your business and industry. The right accountant will do more than file your tax returns — they’ll help you grow, plan, and protect what you’ve built.

Conclusion

Tax mistakes are often unintentional, but they can be expensive. The good news? They’re also avoidable with the right guidance and planning.

If your business is growing and you want to make sure your tax strategy is working as hard as you are, get in touch with Doyle Accountants. We specialise in helping successful business owners take control of their finances and reduce stress around tax time.