Amending Your Constitution Under The Companies Act (2026 Updated)

When you set up a company, your constitution often starts out as a “nice to have” document - until your business grows, you bring in investors, a co-founder leaves, or you hit a decision that your current rules just don’t cover.

That’s usually when people realise the constitution isn’t just paperwork. It’s a practical rulebook for how your company runs, how decisions get made, and what happens when things change.

This guide is current as at 2026 and walks you through how amending a company constitution works under the Companies Act 1993 in New Zealand, what to watch out for, and how to avoid getting stuck with rules that don’t match how you actually operate.

What Is A Company Constitution (And Why Would You Amend It)?

A company constitution is a set of internal rules that governs how your company operates. It usually covers things like:

• how shares can be issued or transferred
• how directors are appointed or removed
• voting rights and decision-making processes
• shareholder rights and protections
• how meetings are run (shareholder and director meetings)

In New Zealand, a company doesn’t have to have a constitution. If you don’t adopt one, the “default” rules in the Companies Act 1993 apply.

But once you do have a constitution, it becomes a key part of your governance - and amending it is one of the main ways you update your company’s rulebook as your business evolves.

Common Reasons Companies Update Their Constitution

Amending your constitution is often triggered by a real-world change. For example:

• Bringing in new shareholders or investors and needing clearer share transfer and pre-emptive rights rules.
• Changing director or shareholder decision-making thresholds (for example, requiring special approvals for big spending or issuing shares).
• Creating different share classes (e.g. ordinary shares vs preference shares) with different rights.
• Aligning governance with a shareholders agreement (or fixing inconsistencies between documents).
• Preparing for a sale or restructure, where buyers often expect clean and current governance documents.

If you already have a Company Constitution, it’s worth checking whether it still reflects how the company actually operates today - not just how it operated when you first registered.

How Does Amending A Constitution Work Under The Companies Act 1993?

The Companies Act 1993 sets out the basic mechanics for altering (amending) a constitution. In plain terms, you usually need:

• the right process (proper resolutions and notice); and
• the right voting threshold (usually a special resolution).

Most amendments require a special resolution of shareholders. A special resolution generally means approval by 75% of the votes of those entitled to vote and voting on the resolution (unless your constitution sets a higher threshold).

In practice, that usually looks like:

1. drafting the proposed amendment (or a full replacement constitution)
2. giving notice to shareholders of the meeting or proposed written resolution
3. passing the special resolution properly
4. updating your company records
5. notifying the Companies Office where required

Do You Amend The Constitution Or Replace It Entirely?

You can do either, and the best approach depends on how much is changing.

• Minor update: You might amend a clause or two (for example, updating director appointment rules).
• Major update: If the document is outdated, inconsistent, or full of tracked changes, it’s often cleaner to adopt a new constitution “in substitution” for the old one.

From a risk perspective, clarity matters. If your constitution is hard to read or conflicts with your other governance documents, it can slow down decisions and create disputes.

What If Your Constitution Has Extra Requirements?

Some constitutions add extra requirements on top of the Companies Act - for example:

• requiring a higher voting threshold than 75%
• requiring approvals from a particular share class
• requiring director consent before an amendment can be proposed

This is why it’s important to check your existing constitution carefully before you start the amendment process. The Act provides the baseline, but your constitution can set more stringent internal rules.

Step-By-Step: A Practical Process For Updating Your Constitution

If you’re a founder or director trying to get this done efficiently (and correctly), here’s a practical roadmap.

1) Review Your Current Governance Setup

Before drafting anything, get clear on what documents currently govern the company and where the “rules” actually sit, such as:

• your constitution
• any Shareholders Agreement
• any investor term sheets or side letters
• board policies and internal delegations

Look for mismatches. For example, if your shareholders agreement says one thing about share transfers, but your constitution says another, you can end up with confusion (or disputes) when someone tries to sell or exit.

2) Work Out What You’re Trying To Achieve

This sounds obvious, but it’s where a lot of businesses get stuck. Ask:

• What problem are we solving?
• What future scenario are we planning for (investment, growth, sale, succession)?
• Are we trying to protect minority shareholders, or make decisions faster, or both?

A constitution amendment is a chance to reduce friction and add certainty - but only if the changes match how you operate (and how you want to operate).

3) Draft The Amendments (Don’t Rely On A Generic Template)

Constitution clauses are highly interconnected. Tweaking one part (like share issue provisions) can unintentionally affect:

• voting rights
• director powers
• minority protections
• future fundraising flexibility

That’s why it’s usually risky to DIY the drafting with a template. A lawyer can help make sure the amendment is internally consistent, enforceable, and aligned with your other documents.

4) Pass The Right Shareholder Resolution

Most amendments need a special resolution. Depending on how your company operates, this can be done via:

• a shareholders’ meeting (with proper notice and agenda); or
• a written resolution signed by the required majority of shareholders.

If your company has a sole shareholder (or a very tight shareholder group), written resolutions can be a quick and clean way to approve the change - but they still need to be done properly and stored in the company records.

If you need to record decisions at a director level as well (for example, approving the proposed amendment and calling a shareholders’ meeting), it can help to document this with a Directors Resolution.

5) Update Your Registers And Company Records

After the constitution is amended, you should update your internal records so there’s a clear paper trail. This typically includes:

• keeping the signed special resolution with your minute book
• keeping a clean copy of the updated constitution (dated, and ideally marked as the current version)
• updating any governance packs you share with directors/shareholders

If the amendment affects share rights, share classes, or transfer restrictions, you may also need to ensure your share register and any shareholder communications are consistent with the new rules.

6) Notify The Companies Office If Required

Some changes need to be filed or updated with the Companies Office (for example, adoption of a constitution and certain updates). The precise requirements depend on what you’re changing and what is already on the public register.

If you’re unsure, it’s worth getting advice - filing the wrong thing (or missing a filing) can create delays and messy clean-up later, especially if you’re fundraising or selling.

Key Legal Issues And Pitfalls To Watch Out For

Most constitution amendments don’t fail because the business “didn’t mean to do it”. They fail because the process was informal, documentation was incomplete, or the amendment created unexpected consequences.

Here are the big risk areas we commonly see.

Accidentally Breaching Shareholder Rights

Constitutions often contain protections for particular shareholders (especially minority shareholders) or particular share classes.

If an amendment:

• changes the rights attached to shares, or
• changes voting rights or dividend rights, or
• removes a key protection

…you may need additional approvals beyond the standard 75% special resolution (for example, approval from the affected class of shareholders).

This is a classic “sounds simple, isn’t simple” scenario - and it’s a big reason to get the amendment reviewed before it’s put to a vote.

Misalignment Between The Constitution And Shareholders Agreement

Your constitution is a public-facing governance document (in the sense it can be filed and is often requested in due diligence), while a shareholders agreement is usually private.

They should work together - not compete.

For example, if your shareholders agreement says there are pre-emptive rights on share transfers, but your constitution is silent (or inconsistent), you can end up with:

• confusion about which rules apply
• disputes when someone exits
• practical issues when the board processes a transfer

Often, a constitution update happens at the same time as a shareholders agreement refresh, or at least with a careful cross-check of both.

Forgetting About Future Fundraising And Dilution

Founders sometimes amend the constitution to solve a “today” issue, but the wording accidentally makes fundraising harder later.

For example:

• overly strict share issue approval rights can slow down capital raising
• vague rules about share classes can cause confusion with investor expectations
• missing drag/tag provisions can make an eventual sale much harder

It’s worth approaching amendments with a growth mindset: “Will this still work if we double in size, raise capital, or bring in a strategic partner?”

Not Keeping Proper Records (And Paying For It Later)

Even if everyone agrees informally, poor documentation can cause problems later - especially if:

• a shareholder relationship deteriorates
• you’re doing due diligence for investment or a sale
• the company gets audited or you need to prove authority for a decision

Clean records are part of good governance. They’re also part of protecting directors and the company if a decision is challenged.

Do You Need A Lawyer To Amend A Constitution?

You’re not legally required to use a lawyer, but for most growing businesses, it’s one of those areas where getting it right upfront saves time, cost, and stress later.

A constitution is not just a “form”. It’s a legal document that can directly affect:

• control of the company
• how decisions can be made and challenged
• how shares can be sold or transferred
• how disputes play out between shareholders

It can also interact with directors’ duties and company decision-making standards under the Companies Act 1993. If you’re making changes around director powers, conflicts, or approvals, it’s worth checking that the approach matches your governance obligations and day-to-day realities.

If your update is part of a wider restructure - for example, changing ownership or bringing in/out shareholders - it can be smart to look at the bigger picture too, including Changing Company Ownership and whether other documents need updating at the same time.

When It’s Especially Worth Getting Advice

It’s usually a good idea to get legal help if you’re dealing with any of the following:

• new investors, a capital raise, or issuing a new class of shares
• exit scenarios, founder separation, or share transfer disputes
• minority shareholder protections (or removing them)
• alignment with a shareholders agreement or other complex governance documents
• preparing for a sale or due diligence process

If you’re also updating the share split, rights, or restrictions, you might need supporting documents beyond the constitution - and those should be consistent with the amendment.

Key Takeaways

• A company constitution is your company’s internal rulebook, and amending it is a practical way to keep governance aligned with how your business actually operates.
• Under the Companies Act 1993, amending a constitution usually requires a special resolution of shareholders (commonly 75% approval), but your constitution may impose additional requirements.
• A clean process matters: draft the amendment properly, pass the correct resolution, keep clear company records, and make any required updates with the Companies Office.
• Common pitfalls include unintentionally affecting shareholder rights, creating inconsistencies with a Shareholders Agreement, and making fundraising or exits harder down the track.
• While you can technically do it yourself, constitution amendments are often high-impact - getting legal help can prevent expensive governance disputes later.

If you’d like help amending your company constitution (or checking that your governance documents work together properly), you can reach Sprintlaw on 0800 002 184 or team@sprintlaw.co.nz for a free, no-obligations chat.