Can My Employer Demand a Medical Certificate for One Day Off? (Australia 2026)

Yes — under the Fair Work Act, an employer can ask you to provide reasonable evidence for paid sick (personal) leave, and that can include a single day. There's no rule that says evidence is only required for two or more days. What the law requires is that the request is reasonable in the circumstances, and that the evidence would satisfy a reasonable person that you were genuinely unable to work.

Many awards, enterprise agreements and workplace policies set their own evidence thresholds (for example, requiring a certificate after a certain number of single-day absences, or around public holidays), so check yours.

A medical certificate from a doctor is the most common form, but it isn't the only one. A statutory declaration is also accepted where a certificate isn't practical. The evidence doesn't have to disclose your diagnosis — a certificate stating you were unfit for work for the period is enough.

If you genuinely couldn't get a certificate (for example, you were too unwell to see a doctor for a single day), explain that — a blanket refusal to accept any other evidence may not be reasonable.

If your employer's request for evidence is reasonable and you don't provide it, they may be entitled to not pay that period of sick leave — but they generally can't discipline or dismiss you just for one unsupported day, and any disciplinary action must follow a fair process. If you think evidence is being demanded unreasonably or selectively (only of you), that may raise general protections or discrimination issues. The Sick Leave Checker walks your entitlement, and the FairWork Mate advisor can talk through your specific award.

You can require reasonable evidence, but apply the policy consistently and set it out in writing in advance. Demanding certificates from one employee but not others, or rejecting valid evidence, invites a general protections or discrimination claim. If a pattern of absences is the real concern, manage it as a separate, supportive-then-procedurally-fair process — see managing excessive sick leave. General information, not legal advice.