When Australian employers can ask for leave evidence and the reasonable person test

When an employee calls in sick, how much can you ask for? Most Australian business owners know they can request a medical certificate, but far fewer know the legal test that governs the request. Under the Fair Work Act 2009 (Cth), you may require evidence that would satisfy a reasonable person that the employee was entitled to the leave they took. Everything else, from the type of leave to the way you store the certificate, sits inside that test.

This guide sets out the obligations that attach to a simple leave evidence request: who the rules apply to, the evidence you can lawfully demand, your record-keeping and privacy duties, and what a misstep costs. If you run an Australian small or medium business, these are the rules your managers need to know.

Who the leave evidence rules apply to

If you employ staff in the national workplace relations system, which covers most private sector employers in Australia, the National Employment Standards (NES) apply to you, and so do the evidence rules in s 107. The obligation is not limited by industry or headcount, but the detail depends on the type of leave and the employee's work pattern:

Paid personal/carer's leave: full-time and part-time employees accrue 10 days a year. Casual employees do not accrue paid personal/carer's leave, because s 96 counts only periods of service other than casual employment.
Unpaid carer's leave: available to all employees, including casuals, for two days per permissible occasion, so casuals can still be asked for evidence.
Compassionate leave: two days per occasion for all employees, including casuals, where a member of the immediate family or household dies or suffers a life-threatening illness or injury, and in related cases such as stillbirth and miscarriage.
Paid family and domestic violence leave: 10 days in every 12-month period under s 106A, available in full to part-time and casual employees. It does not accumulate from year to year.
Privacy Act coverage: a separate threshold decides your privacy duties. Businesses with annual turnover of $3 million or less are generally exempt from the Australian Privacy Principles under the Privacy Act 1988 (Cth), with exceptions that matter for health information.

The evidence rules attach to whichever of these leave types the employee has taken. Before you demand anything, you need to know which entitlement is in play.

The core duty: evidence that would satisfy a reasonable person

Section 107 of the Fair Work Act does two things. It requires the employee to give notice of the leave, and it allows you to require evidence that would satisfy a reasonable person that the leave was taken for a permitted reason.

The notice can come after the leave has started, as long as it is given as soon as practicable. A certificate issued after the absence is not automatically invalid for that reason alone.

The evidence test has four parts, matching the leave types:

Paid personal/carer's leave: evidence that the employee was unfit for work because of personal illness or injury, or needed to care for an immediate family or household member who was ill, injured or affected by an unexpected emergency, as set out in s 97.
Unpaid carer's leave: evidence of the same kind of care or support need.
Compassionate leave: evidence of the permissible occasion, for example a death or life-threatening illness in the immediate family or household, under s 105.
Family and domestic violence leave: evidence that the leave was taken to deal with the impact of family and domestic violence, under s 106B.

What satisfies a reasonable person? In practice, a medical certificate from a registered health practitioner, such as a GP, that names the employee, confirms they were unfit for work or needed to provide care, and covers the relevant dates. A statutory declaration is commonly accepted where a certificate is not practicable, and many employers treat one as satisfying the test.

Nothing in the Act requires a diagnosis, and a request that goes beyond the reasonable person standard is the most common compliance error. A certificate that states the employee was unfit for work and gives the dates is enough. Asking for the condition, the treatment or the medication is asking for more than the law allows.

The Act sets no minimum length of absence before you can ask. You can request evidence for a single day, or for a pattern of Monday and Friday absences, provided you apply the same standard to everyone. Consistency is part of the test: a demand aimed at one employee is harder to defend as reasonable.

Record what you receive

The evidence rules do not stop at the request. Section 535 of the Fair Work Act requires you to make and keep employee records for seven years, and reg 3.36 of the Fair Work Regulations 2009 (Cth) requires those records to include any leave the employee takes and the running balance of each leave entitlement.

Two details are easy to miss:

Pay slips: reg 3.47 prohibits identifying paid family and domestic violence leave on a pay slip, including any reference to the balance. Pay the leave, but describe it neutrally.
The reverse onus: if you do not keep the required records, s 557C shifts the burden of proof. In proceedings about a leave or payment dispute, you may have to disprove the employee's allegations because your records cannot. The note to s 535 makes this explicit.

A simple HR system that logs the certificate, the dates, the leave type and the balance is the difference between a resolvable dispute and an expensive one.

Treat the certificate like health information

Medical certificates are health information even though the law does not always label them that way. Your privacy obligations depend on your size:

Businesses above the $3 million turnover threshold: bound by the Australian Privacy Principles (APPs) under the Privacy Act 1988 (Cth). Collecting only the minimum evidence you need, storing it securely and limiting access are all APP obligations in substance.
Small businesses: employers with annual turnover of $3 million or less are generally exempt from the APPs under s 6D, but the exemption has limits. There are exceptions, for example where the business itself provides health services, and the exemption never displaces other laws such as Fair Work record-keeping or workplace health and safety duties.
Employee records exemption: even APP-covered employers are exempt for employee records directly related to the employment relationship under s 7B(3). The exemption is narrow. It does not reach records about prospective employees or contractors, and it does not authorise careless handling of health information.

Whichever category you fall into, the practical standard is the same: ask for the minimum, keep the certificate in a secure HR file, and let only the people who genuinely need it see it. For family and domestic violence leave, be even more careful. The employee's circumstances may be sensitive, and the pay slip regulation shows how seriously the scheme treats confidentiality.

Verifying a certificate needs the same caution. If a certificate looks inconsistent, ask the employee to clarify or provide further evidence. Do not call the medical practice to check its authenticity without the employee's written consent. Contacting a health provider behind an employee's back raises real privacy and confidentiality risks, and no provision in the Act authorises it.

If you suspect a certificate is fabricated, do not investigate it yourself. Raise the concern with the employee, give them a chance to respond, and follow your normal disciplinary process.

Keep evidence requests free of discrimination

Section 351 of the Fair Work Act makes it unlawful to take adverse action against an employee because of a protected attribute, and the list includes physical or mental disability, family or carer's responsibilities and subjection to family and domestic violence. A leave evidence policy can cross that line without intending to.

The risk areas:

Penalising illness: refusing a reasonable request, treating a chronic condition differently from a one-off illness, or disciplining an employee for taking leave they were entitled to take.
Uneven application: demanding certificates from one team and not another, or scrutinising absences only for employees with disabilities or caring roles.
Using evidence as a weapon: a pattern of Monday absences may be a performance issue, but it is dealt with through performance management, not escalating evidence demands that no reasonable person would accept.

If an employee needs a reasonable adjustment, for example to attend appointments for a chronic condition, consider whether the leave framework can accommodate it before the situation becomes a dispute.

What happens if you get it wrong

The consequences stack up faster than most owners expect:

Civil penalties: contravening the NES, which includes the leave and evidence provisions, is a civil remedy provision under s 44. Maximum penalties are set in penalty units, and each unit has been worth $330 since 7 November 2024. The Fair Work Legislation Amendment (Closing Loopholes No 2) Act 2024 increased the maximum civil penalties for larger employers, and serious contraventions carry higher caps still. The Fair Work Ombudsman can investigate and litigate these contraventions.
Adverse action: an employee who is disciplined, disadvantaged or dismissed in connection with a leave evidence dispute can bring a general protections claim. Compensation orders and penalties can follow, and the reverse onus on records can leave you defending an allegation you cannot disprove.
Unfair dismissal: if the dispute ends in dismissal, the dismissal must still be defensible as fair in all the circumstances.
Privacy complaints: if you are APP-covered and mishandle a certificate, the Office of the Australian Information Commissioner can investigate and, in serious cases, seek civil penalties.

None of this means you cannot ask for evidence. It means the request itself, the records behind it and the way you use the information all need to be defensible.

A short compliance checklist

Run through these items before your next leave request:

Set the baseline in a written policy: evidence required for any personal/carer's leave, what counts as acceptable evidence, and how and when to submit it.
Keep the policy inside the s 107 test: ask for unfitness and dates, never for diagnosis or treatment details.
Apply the same standard to every employee, including single-day absences and patterns around weekends.
Log every certificate against the employee's record, with the leave taken and the running balance, and keep the records for seven years.
Store certificates securely with access limited to HR and the direct manager.
Never put family and domestic violence leave references on a pay slip.
Never contact a health provider to verify a certificate without written consent.
If patterns of absence concern you, raise them through performance management, not more intrusive evidence demands.

When a lawyer earns their fee

Most leave evidence questions are straightforward, but a few are not. A workplace lawyer can review your leave policy against s 107 and the record-keeping regulations, train managers on what they can and cannot ask for, and advise on the decisions that carry real risk: whether to withhold payment where evidence is refused, whether a pattern of absence should be managed as performance or conduct, and how to respond to a general protections or unfair dismissal claim. If you are considering dismissing an employee over a leave issue, get advice before you act, not after.

The question to ask before you demand anything

Every evidence request comes down to one question: would a reasonable person accept this as proof that the leave was for a permitted reason? The obligations that trip employers up are rarely about asking too little. They are about asking for a diagnosis, keeping records that do not capture the leave balance, and applying the rules unevenly when an employee's absences start to annoy the business.

Before your next request, check the three things that matter most: your policy stays inside the reasonable person test, your records capture the leave taken and the balance, and your managers apply the same standard to every employee. If you can answer all three, the certificate on your desk is doing its job.