Do I Need a Medical Certificate for 1 Day Off Sick? (Australia)

Under section 107(3) of the Fair Work Act 2009, an employee who takes personal/carer's leave must, if required by the employer, provide evidence that would satisfy a reasonable person that the leave is taken for a genuine reason. This applies to absences of any length — including a single day. There's no minimum number of days you must be absent before your employer can request evidence.

This surprises many employees who believe that a medical certificate is only required for absences of two or more days. That two-day threshold exists in some Modern Awards and enterprise agreements as the default trigger, but the Fair Work Act itself does not set a minimum.

Your employer can require evidence for a single day's absence, provided the request is reasonable in the circumstances. However, the evidence doesn't have to be a medical certificate from a GP — the Act refers to evidence that would satisfy a 'reasonable person,' which opens the door to alternative forms of evidence.

The Fair Work Act does not specify exactly what form of evidence is required — it simply says evidence that would satisfy a reasonable person. The most common and widely accepted forms include a medical certificate from a registered health practitioner (GP, dentist, psychologist, physiotherapist, etc.), a statutory declaration — a legally sworn statement that you were genuinely unwell, signed before an authorised witness such as a pharmacist, JP, or police officer, and a pharmacy-issued medical certificate (available from some pharmacies for minor illnesses). Some Modern Awards specify the type of evidence required.

For example, many awards state that 'a medical certificate or statutory declaration' is acceptable evidence. If your award lists specific types of evidence, your employer must accept those types.

An employer cannot insist on a GP certificate if your award accepts a statutory declaration as an alternative. The evidence only needs to confirm that you were unfit for work — it doesn't need to disclose your diagnosis or the specific nature of your illness (and yes, this applies to casuals too).

While an employer generally can require evidence for a single sick day, there are situations where the request may be unreasonable. If you're severely unwell and unable to physically attend a doctor (for example, gastro, migraine, or a highly contagious illness), requiring an in-person GP visit may be unreasonable. In such cases, a telehealth consultation, pharmacy certificate, or statutory declaration should be accepted.

If there's no medical appointment available at short notice (which is common, particularly in regional areas), requiring same-day evidence may be unreasonable — the employer should accept evidence obtained within a reasonable time after the absence. If the employer only requires certificates from specific employees (for example, targeting one person) while not requiring them from others in similar circumstances, this could constitute adverse action or discrimination.

Cost can also be a factor — if the employee would incur significant out-of-pocket costs for a GP visit for a minor one-day illness, this may weigh against reasonableness. The Fair Work Commission considers all circumstances when assessing whether an evidence request was reasonable.

Most Modern Awards include specific provisions about notice and evidence for personal leave. A typical award clause requires the employee to notify the employer as soon as practicable (which may be before or after the absence starts), state the expected duration of the absence, and provide evidence if required by the employer. Many awards specify that evidence is required for absences of more than two consecutive days, or for absences on a day adjacent to a weekend, public holiday, or rostered day off (the so-called 'Monday/Friday rule').

Some awards allow the employer to require evidence for a single day if they have a reasonable basis — for example, if the employee has a pattern of single-day absences. Awards in the hospitality, retail, and healthcare industries often have more detailed evidence requirements due to the operational impact of unexpected absences.

Check your specific award at fairwork.gov.au — the evidence requirements are usually found in the 'Personal/carer's leave' clause. If your award is silent on evidence, the Fair Work Act default applies: the employer can request evidence that would satisfy a reasonable person.

No — if you provide evidence that meets the requirements of the Fair Work Act and your applicable award or agreement, your employer must accept it. An employer cannot refuse a valid medical certificate from a registered health practitioner, can't refuse a statutory declaration if it's accepted under your award, and cannot require you to see a specific doctor chosen by the employer (for the purpose of accessing personal leave — though employers can require independent medical examinations in other contexts). If your employer refuses to accept legitimate evidence and then takes adverse action (such as disciplinary action, withholding pay, or issuing a warning for the absence), this may constitute a contravention of the Fair Work Act.

Taking personal leave is a workplace right, and penalising an employee for exercising that right is adverse action under the general protections provisions. If this happens, document the refusal in writing and consider seeking advice from the Fair Work Ombudsman or your union.

If you are taking a single sick day, notify your employer as early as possible — ideally before your shift starts. Most awards require notice 'as soon as practicable.' A quick phone call, text, or email is usually sufficient. If your employer has a specific notification procedure (such as calling a particular number or using an app), follow it.

If you anticipate that your employer will require evidence, consider a telehealth consultation — many GPs offer phone or video appointments that can result in a medical certificate without an in-person visit. Telehealth certificates are just as valid as in-person ones.

Keep a record of your personal leave balance — you're entitled to 10 days per year (pro-rated for part-time employees), and unused leave accumulates from year to year. If you've exhausted your paid personal leave, you can take unpaid personal leave, but the same notice and evidence requirements apply. If you are frequently unwell, consider whether there is an underlying condition that might benefit from a management plan with your GP, which can also help if your employer questions the frequency of absences.