Payroll underpayments explained:
At some point, many growing businesses uncover a payroll error or underpayment. It might come up through an employee question, an internal review, or a change that doesn’t land the way it should have.
When that happens, the immediate instinct is often to fix the numbers and move on. But in mid-sized Australian businesses, payroll errors are rarely isolated. More often, they point to something deeper in the system — how pay rules were set up, how data flows into payroll, or how exceptions have been handled over time.
That pattern shows up consistently in regulatory activity. Fair Work’s payroll remediation programs have involved more than 1,500 participating businesses, most of them addressing systemic issues rather than one-off mistakes. ATO analysis has also linked around 28% of payroll errors in mid-sized businesses to undocumented knowledge held by individuals, where critical payroll decisions live in people’s heads rather than in systems or documentation.
This is why fixing payroll errors properly usually requires more than a correction. It requires a structured response that resolves the issue safely, explains what happened, and reduces the chance of the same problem returning.
This article takes that approach. It breaks the response into three parts:
- Triage (what to do first)
- Remediation (how to fix the issue properly)
- Prevention (how to stop it coming back).
For broader context on how payroll errors fit into the compliance picture, it’s useful to understand payroll compliance beyond STP. When errors expose deeper structural issues, many businesses also choose to bring in expert payroll support to stabilise payroll while remediation work is underway.
Why payroll errors and underpayments happen in mid-sized businesses
Payroll errors aren’t usually about carelessness. They’re structural.
Common causes include:
- Awards or Enterprise Agreement rules not translated correctly into payroll system logic
- Classifications and pay points not maintained as roles change
- Allowances and penalties that don’t trigger reliably
- Manual workarounds slowly becoming “the process”
- Business changes, such as new sites or rosters, without payroll rules being updated
- Payroll knowledge sitting with one person and not being documented
These patterns are explored in more depth in how Awards and Enterprise Agreements become payroll rules . They’re also why payroll handover risk is such a strong predictor of repeat errors.
The data supports this. Compliance analysis has linked missed Enterprise Agreement overrides to superannuation gaps after workplace changes, while workforce research shows payroll error patterns are far more likely to repeat after payroll staff turnover.
Step 1: Triage what’s happened before fixing anything
The first response sets the tone. Calm, structured triage reduces the risk of creating new problems.
1. Confirm the scope of the issue
Before touching the numbers, understand what you’re dealing with.
Is this limited to one employee, or does it affect a role, site, or group? Is it an isolated input issue, or does it point to a rule or configuration problem?
This matters because issues that look small often aren’t. Audit analysis shows a majority of payroll problems initially described as “one-offs” are later found to be systemic.
2. Contain the issue without introducing new errors
The temptation is to rush a manual fix. That often creates secondary problems.
Containment means stabilising payroll, documenting interim adjustments, and ensuring any temporary fixes are traceable. Fair Work consistently warns that rushed fixes can obscure root causes and complicate later correction.
3. Communicate clearly and calmly
How you communicate now shapes trust. Internally, leaders need clarity on scope, timing and next steps. Externally, affected employees need transparency about what’s being reviewed and how corrections will be handled.
Clear communication is far easier when payroll governance and audit trails already exist.
Step 2: Remediate the root cause, not just the numbers
Remediation is structured work. It’s not about patching outputs and moving on.
4. Identify what actually caused the error
Every remediation effort should start with a clear diagnosis. Is the issue caused by:
- Award or Enterprise Agreement interpretation
- Classification or location data
- Workflow failures, such as late approvals
- Implementation gaps where rules were never fully tested
Many remediation programs trace errors back to payroll implementation prep mistakes that were never corrected.
5. Fix payroll rules, not just outcomes
Correcting the payment without correcting the rule almost guarantees the error will return.
If allowances don’t trigger, overtime logic is wrong, classifications are misaligned, or Enterprise Agreement effective dates were missed, the system rules need to be fixed. This often means revisiting how Awards and Enterprise Agreements are configured, and in more complex cases, using payroll implementation services to correct logic safely.
6. Apply back pay consistently and transparently
Back pay calculations need to be consistent, documented and explainable.
This isn’t just about paying the right amount. It’s about being able to show how amounts were calculated if questions arise later. SME analysis has shown that remediation costs quickly escalate when recalculations aren’t well documented.
7. Document everything as you go
Every change made during remediation should be recorded. What changed, when it changed, and why it changed all matter.
Strong documentation reduces confusion later and lowers risk in follow-up audits. This is payroll compliance beyond STP in practice, not theory.
Step 3: Prevent the same payroll issue from coming back
Prevention is where most businesses fall short. It’s also where the biggest gains are made.
8. Test payroll rules against real scenarios
Payroll rules should be tested against how people actually work.
Public holidays, terminations, role changes, higher duties and roster variations are where errors usually surface. Skipping these scenarios is a common cause of repeat issues.
9. Reduce manual workarounds by rebuilding automation
Manual handling usually exists because rules aren’t complete.
Rebuilding automation so the system does the work reduces reliance on individuals and lowers repeat error rates. This is the aim behind modernising messy payroll.
10. Put governance around payroll changes
Governance creates discipline.
Regular reviews, approval workflows, change logs and clear ownership stop payroll drifting over time and help catch issues early. This is the operating model behind payroll governance done right.
11. Remove single-person dependency
Document rules and processes. Share knowledge. Make sure payroll can run during leave or turnover.
This is why payroll handover risk is a prevention issue, not just an operational one.
When payroll errors signal a bigger problem
Sometimes payroll errors are a symptom, not the problem itself.
If errors keep recurring, payroll is heavily manual despite modern software, no one is confident the rules are correct, remediation work is consuming leadership time, or payroll depends on one person holding everything together, it may be time to reassess the model.
This is often where businesses revisit outsourcing payroll versus running it in-house, not to avoid responsibility, but to stabilise risk.
Payroll errors are system problems, not random mistakes
Payroll errors and underpayments are rarely random. They’re usually the result of a repeatable system issue.
The most effective response is structured:
- Triage to contain the issue
- Remediation to fix the root cause
- Prevention to stop it returning
If you’ve uncovered payroll errors or underpayments and want to resolve them properly without ongoing disruption, take action early.
Request a quote to review and stabilise your payroll setup, fix the root causes, and move payroll from reactive firefighting to long-term confidence through managed payroll services.