By Scott Boladeras | 28 January 2026
Payroll mistakes cost Australian businesses millions every year in Fair Work penalties, back-pay, and ATO enforcement action. Most are avoidable. These are the eight payroll errors we find most often when reviewing Xero payroll setups - and how to fix them before they compound
1. Wrong award classification
This is the most expensive payroll error in Australia. We have over 120 modern awards, each with multiple classification levels carrying different base rates, overtime triggers, and penalty structures. Putting an employee on the wrong classification - or the wrong award entirely - means every pay you've processed for that person is incorrect. The underpayment compounds with every pay run
We see this constantly with tradies. A business hires a labourer, sets them up as Level 1 in Xero, and never updates the classification as their responsibilities grow. Two years later, they're performing Level 3 duties on Level 1 pay. That's a back-pay liability stretching across every pay period since they started
Fair Work penalties for serious underpayment can reach $99,000 per contravention for companies. Under the Closing Loopholes legislation, intentional underpayment is now a criminal offence carrying potential imprisonment
2. Incorrect overtime and penalty rate calculations
Overtime rules vary significantly between modern awards. The Building and Construction General On-site Award triggers daily overtime after 8 ordinary hours. The Clerks Private Sector Award triggers it after 38 hours in a week. Some awards calculate overtime on the base rate only. Others include certain allowances in the overtime base. Using Xero's default overtime settings without configuring them for your specific award almost guarantees errors
A common example - a construction business paying time-and-a-half for all overtime when the applicable award requires double time after the first two overtime hours on a weekday and double time for all Saturday afternoon work. On a crew of 12 working regular overtime, that miscalculation can amount to tens of thousands in underpayment annually
3. Superannuation paid late or on the wrong base
The Superannuation Guarantee rate for 2025-26 is 12%. Miss the quarterly deadline and you're liable for the Superannuation Guarantee Charge (SGC) - the super shortfall, 10% per annum interest, and a $20 administration fee per employee per quarter. The SGC is not tax-deductible. The original super contribution would have been
The Australian Taxation Office (ATO) treats late superannuation as one of the most serious payroll compliance failures. Directors are personally liable for unpaid super through Director Penalty Notices (DPN), and that personal liability applies even if the company is insolvent
Equally common is miscalculating the super base. Ordinary Time Earnings (OTE) includes some payments that businesses routinely exclude - certain bonuses, commission, shift loadings, and some allowances. Each excluded payment that should be included creates a super shortfall that grows every pay period
4. Leave accruals that don't reconcile
Leave balances in Xero should match actual entitlements. They rarely do. The three most common causes include opening balances entered incorrectly during Xero migration, accrual rates that don't match the applicable award or National Employment Standards (NES), and leave taken that was recorded as paid time but never deducted from the balance
This becomes a material financial problem at termination. If accrued annual leave in Xero is overstated, you overpay the final pay. If it's understated, you've underpaid and created a Fair Work claim. For a long-tenured employee, the difference can be thousands of dollars
Long service leave is particularly error-prone because it's state-based legislation. In Western Australia, the qualifying period is 10 years for most employees. In Victoria, employees can access pro-rata long service leave after 7 years. The calculation methods, leave loading rules, and payout conditions differ between every state and territory
5. STP reporting errors in Xero
Single Touch Payroll (STP) reports every pay event to the ATO in real time. If your Xero payroll categories are mapped incorrectly, the ATO is receiving wrong data every pay run - wrong gross wages, wrong PAYG withholding figures, wrong allowance classifications. Your employees see these errors when they lodge their tax returns and the pre-filled data doesn't match their records
The most common Xero STP error is allowances being mapped as ordinary earnings instead of their specific allowance type. This inflates reported income and creates ATO discrepancies that can trigger a payroll review of your business
STP Phase 2 added additional reporting granularity - disaggregated income types, country codes for Working Holiday Makers, and separated gross amounts. If your Xero payroll wasn't reconfigured for Phase 2, every STP lodgement since January 2023 contains reporting errors
6. Contractor vs employee misclassification
Calling someone a contractor doesn't make them one. The ATO and Fair Work assess the substance of the working relationship, not the label on the contract. If a worker has set hours, uses your tools and equipment, can't subcontract their work, and has no genuine ability to generate profit independently - they're likely an employee at law
The financial exposure for misclassification is severe. Back-paid superannuation for the entire engagement period, accrued leave entitlements that were never tracked, PAYG withholding that should have been remitted, and potential Fair Work penalties. The ATO can assess back four years for super shortfalls, and longer if fraud or evasion is involved
7. Not finalising payroll at end of financial year
STP finalisation is due by 14 July each year. This is the process that replaces the old payment summaries - it tells the ATO that your payroll data for the financial year is complete and correct. Until you finalise, your employees can't lodge their tax returns using ATO pre-fill data, and your business is flagged as non-compliant
Finalisation requires more than pressing a button. You need to reconcile your pay run totals against your Business Activity Statement (BAS) PAYG withholding figures, verify that leave balances are accurate, confirm superannuation is fully paid and reported, and resolve any STP discrepancies before submitting. We wrote a detailed guide on everything involved in payroll year end
8. Single-person payroll dependency
If one person holds all the payroll knowledge in your business, every pay run carries key-person risk. When they're sick, pays are delayed. When they resign, the award interpretation logic, Xero setup decisions, and undocumented workarounds leave with them. When they make errors, nobody has the knowledge to catch them
We regularly review payroll setups where a spouse or office manager has been processing pays for years without documentation, without independent review, and without current knowledge of award rate changes or legislative updates. The errors in these setups are typically systemic - wrong from the start and compounding ever since
At minimum, payroll needs written process documentation, a separation between the person processing pays and the person approving them, and periodic independent review
How to find and fix payroll errors
Start with a payroll review. We audit your entire Xero payroll setup - award classifications, pay rates, leave accruals, super calculations, STP category mapping, and year-end compliance. We identify errors, quantify the financial exposure, and build a remediation plan
If the errors require voluntary disclosure to the ATO or Fair Work, we help you through that process. Self-reporting payroll compliance failures before they're discovered results in significantly lower penalties than being caught in an audit
And if managing payroll in-house is creating more risk than it's worth, we can take it over entirely as your outsourced payroll team
Talk to us before a small payroll error becomes an expensive one
