Why the simplest check in bookkeeping is the one that gets skipped the most
Introduction
If there is one thing I could get every business owner to do consistently, it would be this. Reconcile your bank accounts properly.
It sounds simple. And it is. But it is also the single most important thing you can do to keep your books accurate, your BAS correct, and your business in good shape.
I see the consequences of skipped or poorly done bank reconciliations all the time. New clients come to me with books that look fine on the surface, but the moment I compare their accounting software to their actual bank statement, the issues start showing up. Duplicated income, missing expenses, BAS lodged on figures that do not match the bank.
These are not mistakes that happen because someone is careless. They happen because bookkeeping is complex and it is easy to miss things when you are busy running a business. But when no one checks, the errors compound over time until fixing them becomes a much bigger job than it ever needed to be.
This guide explains what a bank reconciliation actually is, why it matters, what can go wrong when it is not done properly, and how to make it part of your routine.
What Is a Bank Reconciliation?
A bank reconciliation is the process of comparing the transactions recorded in your accounting software against the transactions on your actual bank statement. The goal is simple: make sure they match.
Every deposit, every payment, every fee, every transfer. If it appears on your bank statement, it should be in your accounting software. And the closing balance in your software should match the closing balance on your bank statement.
That last part is the key. A lot of business owners click “reconcile” in their software and assume everything is fine. But reconciling in the software only means the transactions you have entered are matched against what the bank feed has imported. It does not confirm that nothing has been missed, duplicated, or recorded incorrectly.
The real check is comparing your software’s closing balance against the actual bank statement. If those two numbers do not match, something is wrong.
Why It Matters More Than You Think
Your bank reconciliation is the foundation everything else sits on. When it is right, everything flows. When it is not, everything downstream is affected.
Your BAS figures are only as accurate as the data behind them. If your bank reconciliation is off, your GST calculations will be off, your PAYG withholding may not match, and your profit and loss will not reflect what is actually happening in the business.
Here is what a proper bank reconciliation catches:
- Transactions recorded twice (duplicated income is one of the most common errors I find)
- Payments that have been missed or not categorised
- Bank fees, interest charges, or direct debits that were not recorded
- Personal transactions accidentally recorded as business expenses
- Timing differences between when a payment was made and when it cleared the bank
Without this check, you are essentially lodging your BAS and running your business based on numbers you have not verified. And the ATO has flagged poor record keeping as one of their top compliance focus areas for 2026.
👉 ATO guide on banking records for business
Why I Am Writing This
This is not a theoretical topic for me. It is something I come across regularly when onboarding new clients.
Bookkeeping can be complex, and we are all human. No matter how experienced someone is, things can get missed when workloads are heavy and deadlines are tight. I have seen it across the board, from business owners managing their own books through to experienced professionals. It is not about who is doing the work. It is about making sure the process includes this one critical check.
Here are some common examples of what can happen when bank reconciliations are overlooked:
- Income recorded twice due to the way transactions were entered, overstating revenue and affecting BAS lodgements.
- BAS lodged without the figures being checked against the actual bank statement, meaning the GST reported to the ATO was not accurate.
- Overdue BAS lodged based on the data in the file without a basic reconciliation first.
These are not unusual situations. They happen more often than you would think. And in every case, a basic bank reconciliation, where the software balance is compared to the actual bank statement, would have caught the issue early.
The good news is that once the process is in place, these kinds of errors become much less likely. It is one of the simplest habits to build, and one of the most valuable.
How to Do a Bank Reconciliation Properly
If you use Xero or QuickBooks, the process is straightforward. But it requires more than just clicking a button.
Here is what a proper bank reconciliation looks like:
Step 1: Match your transactions.
Go through your bank feed and make sure every transaction has been matched and categorised correctly.
Step 2: Check for anything missing.
Look for transactions on your bank statement that have not come through the bank feed. Direct debits, bank fees, interest charges, and manual transfers are commonly missed. If it is on the statement but not in the software, it needs to be entered.
Step 3: Compare the closing balances.
This is the step most people skip. Open your bank statement (the actual PDF or printed statement from your bank) and check the closing balance. Then check the closing balance in your accounting software for the same date. If they match, you are done. If they do not, something has been missed, duplicated, or recorded on the wrong date.
Step 4: Investigate any differences.
If the balances do not match, work through the difference. Common causes include duplicate entries, transactions recorded in the wrong period, uncleared items, or amounts entered incorrectly. Do not just adjust the figure to make it balance. Find the actual cause.
How Often Should You Reconcile?
The short answer is as often as you can. Monthly at a minimum. Weekly or fortnightly is better.
The businesses that find bookkeeping easy are the ones that stay on top of it. A little bit regularly is manageable. Leaving it for three months and then trying to catch up before BAS is due is where the stress comes from.
I always compare it to staying on top of your washing. A load or two regularly is easy. Leaving it all until the weekend makes it feel ten times bigger than it is.
If you are doing your own bookkeeping, set a reminder to reconcile your accounts on the same day each week or fortnight. It takes five to ten minutes when it is done regularly. It takes hours when it is not.
Separate Your Business and Personal Accounts
If you are still running business transactions through a personal bank account, this is the single biggest thing you can do to make your bookkeeping easier.
Mixed accounts create problems at every level. It is harder to track business income and expenses, harder to reconcile, harder to prepare accurate BAS, and it raises red flags if the ATO ever reviews your records.
The ATO specifically requires businesses operating through a partnership, company or trust to have a separate bank account. For sole traders, it is strongly recommended.
While you are at it, consider setting up a separate account for GST and PAYG. Transfer the amounts each time you raise an invoice or do a pay run. It takes five minutes and completely changes how BAS time feels. The money is already set aside, so there are no surprises.
What Happens When You Do Not Reconcile
The consequences of not reconciling are not always immediate. That is part of the problem. Things can look fine for months or even years before the issues surface.
But when they do surface, the cost is real:
- BAS amendments: If your BAS was lodged on incorrect figures, it needs to be relodged. This costs time and money, and may trigger ATO interest charges.
- Overpaid or underpaid GST: Incorrect GST reporting can mean you have paid too much (money lost) or too little (money owed plus interest).
- Inaccurate financial reports: Your profit and loss, balance sheet, and cash flow reports are only as accurate as the data behind them. If the bank reconciliation is wrong, your reports are wrong, and any decisions you make based on them are based on incorrect information.
- Audit risk: The ATO uses data matching to compare what you report against what your bank reports. Significant discrepancies can trigger a review or audit.
- Paying twice for the same fix: If errors go undetected, they eventually need to be corrected. That means paying for the same work to be done again, which is an unnecessary cost that could have been avoided with a simple reconciliation check.
What to Look for in a Bookkeeper
If you are working with a bookkeeper or registered BAS agent, it is worth having a conversation about how they approach bank reconciliation. Most professionals do this as standard, and understanding the process helps you feel confident that your numbers are right.
A few good questions to ask:
- Do you compare the software closing balance against the physical bank statement before lodging BAS?
- How often do you reconcile?
- What checks are in place for duplicate transactions or missing entries?
These are not trick questions. They are just a way of understanding the process and making sure you are both on the same page. You can also check whether your bookkeeper or BAS agent is registered with the Tax Practitioners Board.
Final Thoughts
A bank reconciliation is the simplest and most important check in bookkeeping. It takes five minutes when done regularly, it catches errors before they become expensive, and it gives you confidence that your numbers are actually right.
If you are doing your own bookkeeping, make it part of your routine. Compare your software balance to your bank statement every week or fortnight. Check the closing balances match. If they do not, find out why.
If you work with a bookkeeper or BAS agent, have a chat with them about how they approach reconciliation. It is a great conversation to have, and it helps build confidence in the process.
And if your records have not been reconciled in a while and you are not sure where things stand, get in touch. We can take a look, identify any issues, and get everything back on track.
📞 0402 831 073
📧 kay@kmlbookkeeping.com.au
