When Workplace Custom And Practice Becomes An Implied Contract Term In NZ

If you run a small business, it’s normal to focus on the “written” parts of employment: the role, the pay, the hours, and the policies you’ve carefully put together.

But in New Zealand, what governs the employment relationship isn’t always limited to what’s typed into the employment agreement. Over time, the way work is actually done can start to matter just as much.

That’s where “custom and practice” comes in. Certain workplace habits can become implied terms of an employment agreement - meaning they may be treated as part of the deal, even if you never wrote them down.

This article is general information only and isn’t legal advice. Because employment issues are fact-specific, it’s a good idea to get advice on your particular situation.

In this guide, we’ll break down what that means, how implied terms can form, and what you can do to keep your business legally protected (without having to run a rigid workplace where nothing can ever change).

What Are Implied Terms In Employment Contracts (And Why Do They Matter)?

An employment agreement is made up of:

• Express terms (what you’ve written or clearly agreed to, like pay rate and hours), and
• Implied terms (terms that aren’t written down but can still be part of the contract).

In practice, implied terms can come from a few different places, including:

• The law (for example, duties created by employment legislation or common law),
• The nature of the relationship (like mutual trust and confidence), and
• Custom and practice in your workplace (how things have been done over time).

From a small business owner’s perspective, this matters because implied terms can:

• limit your ability to change work arrangements quickly;
• create unexpected obligations (for example, an annual “bonus” that has quietly become an expectation);
• increase the risk of personal grievances or disputes when you try to remove a long-standing benefit; and
• undermine what you thought your written agreement already covered.

This is one of the reasons it’s so important to have a clear, well-drafted Employment Contract in place from day one - because the clearer your express terms are, the less room there is for assumptions to fill the gaps later.

What Does “Custom And Practice” Mean In An NZ Workplace?

“Custom and practice” is a way of describing workplace patterns that become established through repeated behaviour over time.

It’s not just “we did it once and everyone liked it”. It’s more like:

• you’ve done something the same way for a long time;
• it’s been consistent and predictable;
• employees have come to rely on it; and
• it’s been accepted as “how things work around here”.

When custom and practice becomes strong enough, it can potentially be treated as an implied term - meaning it becomes part of the employment contract, even if your written agreement never mentions it.

Common Examples That Catch Small Businesses Off Guard

Some examples of workplace habits that can evolve into implied terms include:

• Regular overtime arrangements (for example, “we always get time-and-a-half after 5pm” even though the contract is silent)
• Guaranteed hours in practice for an “as-needed” or variable-hours employee who has been rostered consistently for months
• Extra paid days off (for example, a “birthday leave day” given every year)
• Bonuses or commissions that are paid consistently and in a predictable way
• Work-from-home arrangements becoming the default, even if initially described as “temporary”
• Roster patterns that effectively become fixed (“you always work Monday to Thursday”)

None of these are automatically implied terms just because they happened. The risk is when they become entrenched - and you don’t clearly manage expectations around them.

When Can A Workplace Habit Become An Implied Term?

There isn’t one simple checklist that applies to every business, because implied terms are heavily context-based. But there are some practical indicators that a “habit” is moving into implied-term territory.

In general, a custom/practice is more likely to be argued as an implied term where it is:

• Consistent (done the same way each time)
• Long-standing (repeated over a meaningful period)
• Certain and clear (not vague or random)
• Well-known across the business (not just quietly offered to one person one time)
• Relied on by employees when making decisions (for example, budgeting or childcare arrangements)
• Accepted without objection (or at least not clearly stated as discretionary)

A key business takeaway here is that if your team reasonably believes something is part of “the deal”, it becomes much harder to remove without a proper process.

“But It’s Not In The Contract” Usually Isn’t A Complete Answer

It’s tempting to think the written agreement always wins. In reality, what you do in practice can create ambiguity - and ambiguity is where disputes often begin.

Even if your contract says something like “we may change duties” or “bonuses are discretionary”, repeated conduct can still create expectations in some situations. For example, if a “discretionary” bonus has been paid every year like clockwork (especially using a consistent approach or criteria), you may need to handle any change carefully.

That’s why your contract and your real-world practices need to line up. If they drift apart, your legal risk usually increases.

Why Implied Terms Create Risk When You Want To Change Work Arrangements

For small businesses, change is part of survival. You might need to change opening hours, reduce overtime, restructure roles, or introduce more formal policies as you grow.

The problem is: if a workplace habit has become an implied term, changing it can look like changing the employment agreement - and in NZ, you’ll often need to follow a good-faith process and (in many cases) reach agreement rather than simply changing it on your own.

Common “Change Points” Where Issues Pop Up

We often see custom-and-practice disputes arise when a business tries to:

• reduce hours after a long period of consistent rostering (especially where staff have come to rely on the pattern);
• stop paying an allowance that has been paid routinely;
• change commission structures or KPIs without agreement;
• remove flexible arrangements that have become the norm;
• introduce stricter rules (like enforcing clock-in times) after years of informality.

If you’re already thinking about a restructure, roster changes, or cost-saving measures, it’s worth getting advice early - especially where you know there are long-standing practices in your workplace. A change that seems operationally reasonable can still trigger legal obligations around consultation and agreement.

For example, if you’re looking at changing rosters or cutting shifts, issues can overlap with broader questions about reducing staff hours lawfully and fairly.

How To Manage Custom And Practice Without Killing Workplace Flexibility

You don’t need to run a cold, inflexible workplace to avoid implied terms. What you do need is clarity.

Here are practical steps that help reduce risk while still keeping your business agile.

1. Make Sure Your Written Agreements Match Reality

If your employment agreements say one thing, but you’ve operated differently for years, that’s a red flag.

It may be time to update your documentation (and do it properly). This might include:

• updating the employment agreement wording;
• using schedules for role-specific entitlements (like allowances or commission);
• documenting whether certain benefits are discretionary or temporary.

If you’re issuing employment agreements, it’s also worth checking whether you’re using the right type of agreement for the reality of the role (for example, genuinely intermittent “casual” work vs ongoing part-time or full-time work). Misalignment here can cause bigger problems than you might expect.

2. Be Careful With “Informal Promises” (Even If You Mean Well)

Small business owners often offer perks to be supportive - especially when trying to retain good staff.

That’s great for culture. The risk is when those perks are communicated as an entitlement rather than a one-off.

For example:

• “We’ll always let you leave early on Fridays” is very different from “We can be flexible where we can, depending on business needs.”
• “We’re giving everyone a bonus every December” is very different from “We may offer a discretionary bonus depending on performance and business results.”

If you want something to remain flexible, you need to describe it that way - and keep the message consistent.

3. Put Policies In Writing (And Ensure They’re Used)

Policies can help set boundaries around how things are done. But they only help if they’re:

• clear and accessible;
• actually followed in practice; and
• reviewed as your business grows.

For example, if you have a policy around confidentiality and sensitive information, you should ensure it’s reinforced in onboarding and day-to-day operations. Where you need contractual backing, a properly drafted Confidentiality Clause can be critical, particularly if employees have access to pricing, supplier lists, or client data.

4. Use “Temporary” Arrangements Properly

Sometimes you genuinely need a temporary measure - a short-term roster change, a temporary allowance, or a flexible arrangement during a busy period.

The mistake is not labelling it as temporary, and not setting a review point.

To keep things clean, you can:

• confirm the arrangement in writing (even a simple letter or email can help);
• state why it’s being offered;
• state the review date or end date; and
• make clear it doesn’t change the underlying employment agreement unless expressly agreed.

This kind of paper trail won’t solve every issue, but it can make a big difference if you later need to explain why a benefit was never intended to be ongoing.

What Should You Do Before You Remove A Long-Standing Workplace “Perk”?

If you’re considering removing (or scaling back) something your team has come to expect, treat it as a change-management exercise - not just an operational tweak.

Even where you believe you’re legally entitled to change the arrangement, handling it poorly can still lead to disputes, resignations, and reputational damage.

A Practical Process You Can Follow

Before making the change, it’s usually worth:

• Checking the employment agreement and any written policies or communications;
• Reviewing how long the practice has been in place and how consistently it’s been applied;
• Considering whether employees rely on it (for example, set childcare pickup times);
• Assessing whether you need employee agreement to vary the arrangement;
• Consulting with staff and genuinely considering feedback;
• Confirming the final decision in writing, including when it takes effect.

If the change is connected to performance issues (for example, tightening up on attendance or breaks), it’s still important to proceed carefully and fairly. The Employment Relations Act 2000 places obligations on good faith behaviour, and fair process matters.

If you’re moving towards formal disciplinary or exit steps, it’s also worth understanding how termination obligations can work in practice - including issues like payment in lieu of notice where relevant and properly documented.

Don’t Accidentally Create A Second Implied Term When You “Fix” The First

One sneaky risk: you remove one long-standing benefit, but replace it with another informal workaround that becomes the new custom.

For example, you stop paying overtime, but managers start letting staff leave early on quiet days as an “unofficial” swap. If that happens consistently, you can end up with a new implied entitlement (and the original problem repeats).

If you want flexibility, it usually needs a framework - not an unspoken bargain.

Key Takeaways

• In NZ, implied terms can form in employment agreements even when you never wrote a term down - including through workplace custom and practice.
• A workplace habit is more likely to be argued as an implied term if it’s consistent, long-standing, clear, relied upon, and widely accepted in your business.
• Implied terms can limit your ability to change arrangements quickly, especially where employees have come to rely on a particular benefit or pattern of work.
• You can reduce risk by ensuring your written agreements match reality, documenting “temporary” arrangements properly, and communicating clearly about what is (and isn’t) an entitlement.
• Before removing a long-standing perk or practice, it’s smart to check the contract, consult with staff, and confirm any change in writing to protect your business.
• Having the right legal foundations in place from day one - including a clear Employment Contract and well-managed policies - can help you avoid costly disputes later.

If you’d like help reviewing your employment agreements or managing a proposed workplace change, you can reach us at 0800 002 184 or team@sprintlaw.co.nz for a free, no-obligations chat.