Medical Certificates And Sick Leave Evidence Requirements In New Zealand

If you run a small business, sick leave can be one of those “simple in theory, tricky in practice” parts of employing staff.

On the one hand, you need to support your team and meet your legal obligations. On the other hand, you still need to manage rosters, deadlines, clients, and budgets - and sometimes you just need to know whether you can ask for proof.

This guide breaks down how medical certificates (and other acceptable evidence) for sick leave work in New Zealand, when you can ask for them, who pays, and how to handle the process in a fair (and legally safer) way. (This article is general information only and not legal advice.)

What Are Your Legal Obligations Around Sick Leave In New Zealand?

In New Zealand, employee sick leave is mainly governed by the Holidays Act 2003.

As an employer, your practical obligations usually fall into three buckets:

• Providing sick leave entitlements to eligible employees (and letting them use it when they’re unwell or injured).
• Paying sick leave correctly (including following the correct “relevant daily pay” / “average daily pay” approach where applicable).
• Managing evidence requests fairly if you need proof (including when and how you can request a medical certificate or other evidence for sick leave).

It’s also worth remembering sick leave isn’t only for when an employee personally is sick. Employees may also be entitled to take sick leave to care for a dependent (like a child or someone they look after) who is sick or injured.

One of the biggest risks for small businesses isn’t usually the sick leave itself - it’s inconsistent handling (e.g. asking some staff for proof but not others, or applying different “rules” depending on who the manager is that day).

If you haven’t already, it’s a good idea to make sure your expectations are reflected in your Employment Contract and supported by clear policies and manager training.

When Can You Ask For Medical Certificates For Sick Leave?

This is the big question employers ask: “Can I require a medical certificate for sick leave?”

Generally, yes - but there are rules around timing and cost.

1) After 3 Consecutive Calendar Days Of Sick Leave

Under the Holidays Act framework, if an employee has been on sick leave for 3 or more consecutive calendar days, you can ask them to provide proof of sickness or injury (commonly a medical certificate).

A few practical points that trip people up:

• It’s calendar days, not working days (so weekends and non-work days can count if they fall within the period of absence).
• The “3 days” is about consecutive days of being sick, not necessarily consecutive rostered shifts.
• You should communicate the request as early as reasonably possible once you know the absence will meet the threshold.

2) Within The First 3 Days (But Only If You Pay)

Yes, you can ask for proof (including a medical certificate) before day 3 - but only if you agree to pay the employee’s reasonable costs of getting that proof.

This is often used when there’s a genuine operational need (e.g. you’re making urgent rostering decisions), or where there’s a pattern you need to address carefully.

For small businesses, a helpful way to think about it is:

• If you’re requesting proof early, you’re choosing to absorb the cost because it’s important for the business.
• If you’re requesting proof after 3 consecutive calendar days, the employee is generally responsible for obtaining it.

In either scenario, it’s important to keep your approach consistent and not punitive. If you’re using medical certificate requests as a “discipline tool”, you can create unnecessary legal risk.

Who Pays For Medical Certificates For Sick Leave (And What Counts As “Reasonable Costs”)?

Cost is where a lot of employer/employee tension can creep in.

If you request proof within the first 3 consecutive calendar days of sick leave, you generally need to pay the employee’s reasonable costs of getting it.

“Reasonable costs” isn’t always a fixed number, but commonly includes things like:

• a standard GP consultation fee (or other health practitioner fee);
• fees charged specifically to issue a medical certificate;
• in some situations, other necessary costs where appropriate (this can be fact-specific).

In practice, to avoid disputes:

• Tell the employee in writing that you’re requesting proof and that the business will cover reasonable costs.
• Clarify what you need (e.g. “a medical certificate confirming you’re unfit for work for [date range]”).
• Decide how you’ll reimburse (e.g. payroll reimbursement on receipt, company account/payment where possible).

If you request proof after 3 consecutive calendar days, the employee usually pays to obtain it.

That said, if you operate in a high-trust workplace (or you want to encourage staff to seek care without cost barriers), some businesses choose to reimburse anyway. If you do this, make sure it’s done consistently, and clearly documented as a discretionary benefit rather than an entitlement.

What “Proof” Can You Request Besides A Medical Certificate?

When people say “medical certificate”, they often mean a GP note - but under the Holidays Act, “proof” will usually be a medical certificate or other evidence of sickness or injury from a relevant health practitioner.

The key is that whatever you ask for should be:

• reasonable in the circumstances, and
• appropriate for the type and length of absence, and
• handled confidentially.

Depending on the situation, proof might be:

• a medical certificate from a GP;
• a certificate or letter from another qualified health practitioner.

Be careful about asking for too much medical detail. As a general rule, you usually only need confirmation of:

• the employee is/was unfit for work, and
• the relevant date range (e.g. unfit from Monday to Wednesday), and
• any work restrictions (only if needed for safe return to work).

If you’re dealing with ongoing or complex health issues, it’s smart to get advice before you request additional information - especially because medical information is often treated as sensitive personal information under the Privacy Act 2020.

How To Request Medical Certificates For Sick Leave Without Creating Legal Risk

Most disputes don’t happen because you asked for proof - they happen because of how you asked, when you asked, or how consistently you applied the rule.

Here’s a practical approach many employers use.

Step 1: Make The Request Early And In Writing

If the absence is likely to reach 3 consecutive calendar days, send a quick email or message (whatever your workplace normally uses) confirming:

• you hope they feel better soon;
• you’re requesting proof for the sick leave period; and
• the timeframe to provide it (e.g. “please provide it when you’re able, ideally by your return to work”).

If you’re requesting proof within the first 3 days, add a line confirming you’ll cover reasonable costs and how they should claim it.

Step 2: Keep The Request About Process, Not Suspicion

Even if you’re worried about misuse, it’s usually safer to frame the request as part of a consistent process.

For example, “For absences of 3 days or more we require medical certificates for sick leave,” is generally better than “We need proof because this looks suspicious.”

Step 3: Apply The Same Standard Across The Team

Inconsistency is a common source of personal grievances.

To reduce risk:

• use a standard template message for medical certificate requests;
• train managers on the 3-day rule and payment rule;
• document when and why exceptions are made.

Step 4: Store Certificates Securely (And Limit Access)

Medical certificates contain personal information. Under the Privacy Act 2020, you should only collect what you need, keep it secure, and restrict access to people who genuinely need it for employment administration.

As a baseline, consider:

• storing certificates in a secure HR file (not a shared inbox);
• limiting access to the business owner/HR/finance as needed;
• not discussing the employee’s health details with other staff.

If your business collects and stores personal information more broadly (including employee information), having a fit-for-purpose Privacy Policy and internal processes can make compliance much easier.

Step 5: Be Careful If You Suspect Misuse

Sometimes patterns do raise genuine concerns (for example, repeated “sick days” around weekends, big shifts, or disciplinary meetings).

Even then, jumping straight to discipline can backfire if you don’t follow a fair process. Often, a better first step is:

• a confidential check-in;
• clarifying expectations around notification and proof;
• considering whether there are underlying health or personal issues you need to accommodate.

If you are moving toward a formal process, it’s worth getting advice early so your approach stays compliant and fair - particularly if termination could become a possibility. (If you’re navigating a difficult situation, the process matters as much as the outcome.)

Special Situations: Ongoing Illness, Mental Health, And Return-To-Work

Short, straightforward sick leave is one thing. Ongoing or sensitive health issues are another.

Small businesses often ask: “Can I ask for more information if the employee keeps taking sick leave?”

In some situations, you may be able to request additional information, especially where you need to:

• understand whether the employee can safely return to work;
• consider adjustments or temporary duties;
• manage operational impacts from prolonged absence.

However, you should tread carefully. The employee’s health information is personal, and you generally shouldn’t be requesting detailed diagnoses unless there is a genuine need connected to the role.

Mental Health And Stress Leave

Mental health can absolutely be a legitimate reason for sick leave.

From an employer perspective, it can help to focus on what you need to manage the workplace:

• confirmation the employee is unfit for work (or fit with restrictions);
• the likely timeframe; and
• any support or adjustments recommended (where relevant).

It’s also worth remembering you have obligations under health and safety law to provide a safe work environment, including managing psychosocial risks where they’re relevant.

Return-To-Work Plans And Restrictions

If an employee is returning after illness or injury, you may need to understand restrictions (for example, “no heavy lifting” or “shorter shifts for two weeks”).

This is where a medical certificate or fit note can be genuinely useful - not as “proof”, but as a tool to help you bring someone back safely.

If you need to adjust duties, hours, or the work environment, document it clearly. If you’re changing work arrangements more broadly, you may also want to review your contracts and policies so you’re not making informal arrangements that later become messy.

Key Documents And Policies That Make Sick Leave Management Easier

If you’re finding sick leave conversations are happening ad hoc (and always under pressure), that’s usually a sign your business needs clearer foundations.

For most small businesses, the goal is to make sick leave management:

• consistent across staff,
• easy for managers to apply, and
• fair and legally compliant.

Some helpful documents and tools include:

• Employment agreements that clearly explain sick leave notification requirements and proof rules (your Employment Contract is usually the right place to set this out).
• A leave policy or handbook section that explains practical expectations (who to call, by when, what happens if the absence extends, when medical certificates may be required for sick leave).
• A privacy-aware HR process for collecting, storing, and disclosing medical information (supported by your Workplace Policy and privacy processes).

If your business is growing and different managers handle leave differently, tightening up your documentation can save a lot of time (and prevent disputes) later.

Key Takeaways

• In New Zealand, you can generally request a medical certificate for sick leave (or other health practitioner evidence) when an employee is away sick for 3 or more consecutive calendar days.
• You can request proof within the first 3 consecutive days, but if you do, you generally need to pay the employee’s reasonable costs of obtaining the proof.
• “3 consecutive days” is based on calendar days, so weekends and non-work days can still count if they fall within the continuous absence.
• When requesting proof, keep your approach consistent, request only what you reasonably need, and avoid framing requests as punishment or suspicion.
• Medical information should be treated as personal (often sensitive) information - store it securely, limit access, and don’t collect more detail than you need.
• Clear documentation (like an Employment Contract, a Workplace Policy, and a Privacy Policy) makes sick leave management much smoother as your team grows.

If you’d like help reviewing your employment documents or setting up a clear, legally compliant approach to sick leave and medical certificates, you can reach us at 0800 002 184 or team@sprintlaw.co.nz for a free, no-obligations chat.