Sub-Contracting And Head Contracts: Here’s What You Need To Know (2026 Updated)

If you run a business that delivers work through other people (tradies, consultants, creatives, developers, labour hire teams, specialist subcontractors), sub-contracting can be a smart way to scale without hiring employees.

But it only works smoothly when the “head contract” (your contract with the client) and the subcontract (your contract with the person doing the work) line up. If they don’t, you can end up wearing cost, delay, and liability you never priced in.

This 2026 update reflects what we’re seeing across New Zealand projects right now: tighter procurement requirements, more emphasis on health and safety and data handling, and clients expecting clearer accountability even when you’re outsourcing parts of the job.

Below, we’ll break down how head contracts and subcontractor agreements work, what to watch for, and what to put in writing so you’re protected from day one.

What Are Head Contracts And Subcontracts (And Why Do They Matter)?

In plain terms:

• The head contract is the agreement between you (the main contractor/service provider) and your client.
• The subcontract is the agreement between you and your subcontractor (the person/business you engage to do part of the work).

It sounds straightforward, but here’s the key point: your client generally has a contract with you, not your subcontractor. That means if something goes wrong (defects, delays, data issues, safety incidents), the client usually comes to you first.

So the legal goal is simple:

• make sure your head contract clearly defines what you owe the client, and
• make sure your subcontract clearly defines what the subcontractor owes you (so you can actually deliver on your head contract).

If the documents don’t match, you can end up in a “contract gap”, where you’re liable to the client but can’t pass responsibility (or costs) down to the subcontractor.

A Quick Example Of A Contract Gap

Imagine you’re a building contractor. Your head contract says the works must be completed by a fixed date and any delay triggers liquidated damages.

You subcontract part of the job (say, electrical) on a casual email chain with no deadline and no delay consequences. The electrician runs late. The client hits you with delay costs. You try to recover it from the subcontractor and realise there’s nothing enforceable in writing.

This is why “we’ll sort it out later” can become very expensive, very quickly.

When Should You Use A Subcontractor (And When Is Employment A Better Fit)?

Subcontracting is common in construction, cleaning, IT, marketing, logistics, events, property services, and professional services. It can also be the right approach when you need specialist expertise for a short period.

But you do need to be careful about one big issue: misclassification.

Just calling someone a “contractor” doesn’t automatically make them a contractor. In New Zealand, whether someone is really an employee depends on the real nature of the relationship (control, integration into the business, independence, who provides tools, financial risk, and so on).

If you treat someone like an employee but pay them like a contractor, you can create major issues around:

• holiday and leave entitlements
• PAYE and tax obligations
• minimum employment standards and termination processes
• vicarious liability and health and safety responsibilities

Where the person is genuinely running their own business, taking on commercial risk, and controlling how they do the work, a contractor model may make sense. If they’re basically part of your team on set hours under your direction, you may be better off using an Employment Contract.

If you’re unsure, getting tailored advice early is worth it-fixing a misclassification problem later is much harder (and usually more costly).

What Should Your Head Contract Cover Before You Engage Subcontractors?

Your head contract is the “top layer” of obligations. Before you bring in subcontractors, you want to know exactly what you’ve promised the client-because those promises drive what must appear in your subcontract.

While every industry is different, most head contracts should clearly address:

1) Scope Of Work And Deliverables

Define what is included, what is excluded, and what assumptions you’re relying on. If the scope is vague, it’s harder to manage variations and harder to prove when extra payment is due.

2) Timing, Milestones, And Delay Risk

Key questions to clarify:

• Is the delivery date fixed, or “best endeavours”?
• Are there milestones and sign-off stages?
• Are there consequences for delay (like liquidated damages)?
• Do extensions of time apply for weather, supply chain issues, late client input, or force majeure?

Once you understand the timing risk you’re carrying, you can decide how much of that risk can (and should) be passed down to subcontractors.

3) Payment Terms And Cashflow

Your head contract should set out:

• how and when you invoice
• when the client must pay
• what happens if payment is late
• whether retentions, holdbacks, or staged payments apply

Be cautious with “pay when paid” arrangements. They can create cashflow pressure and may be hard to enforce in some situations depending on how they’re drafted and the surrounding circumstances.

4) Liability, Indemnities, And Insurance

This is where head contracts often get intense. Clients may ask for:

• caps on your liability (or, sometimes, no cap)
• indemnities for third-party claims
• specific insurance cover (public liability, professional indemnity, contract works, cyber)

If you agree to an indemnity that’s broader than what your subcontractors accept, you’re exposed.

5) Confidentiality And Data Handling

Even if you’re not a “tech business”, you may still handle personal information (names, addresses, CCTV, medical details, payment information). The Privacy Act 2020 expects you to take reasonable steps to protect personal information and only use/share it appropriately.

If your subcontractors will access client or customer data, it’s worth having clear privacy obligations in place and making sure your internal approach is consistent with a Privacy Policy (especially if you collect info through a website or online booking form).

6) Variations And Change Control

Projects change. The real question is whether your contract makes it easy to manage changes without disputes.

Your head contract should cover:

• how variations are requested and approved
• how price/time impacts are calculated
• what happens if the client asks you to proceed urgently before paperwork is signed

What Should A Subcontractor Agreement Include (So It Matches The Head Contract)?

Your subcontractor agreement is where you protect your delivery model. It’s not just about “hiring someone to help”-it’s about making sure the subcontractor’s obligations support your promises to the client.

If you’re engaging subcontractors regularly, having a properly drafted Sub-Contractor Agreement is one of the simplest ways to prevent avoidable disputes.

1) Scope, Standards, And Specs

Be specific about:

• exact deliverables
• materials/specifications/standards that must be followed
• who supplies what (materials, tools, software licences)
• what “done” means (and what acceptance looks like)

If your head contract includes performance standards, you generally want those standards reflected in the subcontract too.

2) Timeframes And Coordination Requirements

Subcontractor delays are one of the most common causes of client disputes. Your subcontract should address:

• start and finish dates (or milestones)
• attendance on site / availability windows
• notice requirements if the subcontractor anticipates delay
• handover and sign-off processes

If your head contract includes delay damages, you may also consider whether your subcontract should include delay costs or other remedies (appropriately drafted for your circumstances).

3) Payment Terms (And What Happens If The Client Doesn’t Pay)

Your subcontract should clearly state:

• the subcontract price and what it includes
• how invoices must be issued (including required supporting documents)
• payment timeframe
• when you can withhold payment (for defects, incomplete work, backcharges)

This is also where businesses often want to include “pay when paid” wording. If you’re considering this, it’s worth getting it drafted carefully-because a clause that isn’t enforceable won’t help you when cashflow gets tight.

4) Flow-Down Clauses (Passing Head Contract Obligations Down)

A common approach is to “flow down” relevant obligations from the head contract into the subcontract.

This can include things like:

• health and safety requirements
• site rules and client policies
• confidentiality and data handling
• quality standards and inspection regimes
• warranties and defect rectification obligations

The goal isn’t to dump your entire head contract on the subcontractor. It’s to ensure any obligations that affect their work are enforceable against them.

5) Defects, Rework, And Warranties

Most subcontract disputes come down to one painful question: who pays to fix it?

A good subcontract will set out:

• defects liability period (if any)
• timeframes for rectification
• what happens if the subcontractor doesn’t fix defects (step-in rights / backcharge)
• how warranties are provided and documented

This is also where you can align with how “warranties” are treated in New Zealand more broadly, including under consumer protection rules where relevant.

6) IP Ownership And Deliverables

If your subcontractor is creating anything (designs, code, marketing materials, reports, manuals, training content), you should be clear about who owns the intellectual property and what licences apply.

Without clear wording, you can end up unable to hand over what the client paid for-or unable to reuse work you thought you owned.

7) Termination And Step-In Rights

Your head contract might allow your client to terminate for certain reasons. You should consider whether your subcontract should give you similar rights, such as termination for:

• serious breach
• poor performance or repeated defects
• failure to meet deadlines
• health and safety breaches
• insolvency

“Step-in rights” can also be important on projects where delay risk is high. This gives you the ability to take over part of the work (or engage someone else) if the subcontractor fails to perform.

Key Legal Risks In Sub-Contracting (And How To Reduce Them)

Subcontracting isn’t just an operational decision-it’s risk allocation. These are some of the biggest legal and commercial risks we see for NZ businesses, and the practical ways to manage them.

1) You’re Still On The Hook To The Client

Even if a subcontractor causes the problem, your client’s rights are typically against you under the head contract.

How to reduce the risk:

• use strong “flow-down” obligations in the subcontract
• require subcontractor insurance where appropriate
• include remedies like rectification obligations, backcharge, and indemnities (carefully drafted)

2) Health And Safety Duties Can’t Be Outsourced

Under the Health and Safety at Work Act 2015, businesses have duties to ensure, so far as reasonably practicable, the health and safety of workers and others.

On many projects, multiple parties are PCBUs (persons conducting a business or undertaking) and need to consult, cooperate, and coordinate.

How to reduce the risk:

• make sure your subcontract requires compliance with your health and safety systems
• record site induction requirements and incident reporting
• clarify who is responsible for supervision, plant, and PPE

3) Misleading Claims And Client Promises

If you market services or make representations about timelines, quality, compliance, or pricing, you need to ensure they’re accurate. The Fair Trading Act 1986 applies broadly to business conduct and can create real exposure if a customer or client says they were misled.

How to reduce the risk:

• keep marketing and proposals consistent with what your subcontractors can actually deliver
• document assumptions and exclusions in the head contract
• avoid “guaranteeing” outcomes unless you can fully control delivery

4) Confidentiality, Privacy, And Data Security

Subcontractors often access sensitive information: customer lists, pricing, login credentials, job files, site access codes, or personal information.

How to reduce the risk:

• include clear confidentiality obligations
• limit access to only what’s needed
• set security expectations (password protection, device security, reporting incidents)
• make sure subcontractors understand they can’t reuse client data for their own purposes

5) Disputes About Variations And Extra Work

Subcontractors may claim they did “extra work” and deserve extra payment, while you may say it was included in scope. This gets messy fast if approvals weren’t documented.

How to reduce the risk:

• include a clear variation process (request, quote, approval, then work)
• train your team not to approve changes casually on-site or via text
• align variation rules between the head contract and subcontract

Practical Checklist: Getting Your Contracts Aligned From Day One

If you want a simple, repeatable approach, here’s a practical checklist you can use before each new project (or whenever you onboard a new subcontractor).

1) Read The Head Contract Like A Risk Document

Before you sign, identify:

• what you’re promising (scope, timing, quality)
• what happens if you miss it (delay costs, rework, termination)
• any special requirements (insurances, security clearances, certifications)

If you’re not sure what a clause really means in practice, it’s worth getting a Contract Review so you understand what you’re actually taking on.

2) Decide What You Need To Flow Down

Not every clause needs to be copied into the subcontract. Focus on obligations that affect the subcontractor’s work or create risk you need to manage.

3) Use A Written Subcontract Every Time

Even if you’ve worked with the subcontractor for years, don’t rely on informal arrangements. People forget details, staff change, and projects become disputed when budgets blow out.

A written subcontract should cover the essentials: scope, time, price, quality, variations, liability, insurance, confidentiality, and termination.

4) Make Sure Your Documents Match How You Actually Operate

This one’s easy to miss. If your contract says you’ll do weekly reporting, quality inspections, or sign-offs-make sure you actually do those things.

Contracts don’t just allocate risk; they create evidence. If a dispute happens, your paper trail matters.

5) Keep Your Broader Business Foundations Tight

Subcontracting sits within your broader legal setup. Depending on your structure and growth plans, you might also want to make sure your company governance is sorted with a Company Constitution or your co-ownership arrangements are clear in a Shareholders Agreement.

This isn’t about paperwork for the sake of it-it’s about avoiding internal disputes while you’re busy delivering work for clients.

Key Takeaways

• In most subcontracting arrangements, your client’s contract is with you, so you’re usually the first party responsible if something goes wrong.
• A “contract gap” happens when your head contract requires something, but your subcontract doesn’t allow you to enforce it against the subcontractor.
• Your head contract should clearly set out scope, timing, payment, variations, liability, confidentiality/data handling, and termination rights.
• Your subcontractor agreement should align with the head contract, including flow-down obligations, quality standards, timeframes, variation rules, and defect responsibilities.
• Be careful not to misclassify workers-if someone is effectively an employee, you may need an Employment Contract rather than a contractor arrangement.
• Health and safety and privacy responsibilities are ongoing, even when you outsource work, so your contracts and processes need to reflect this.
• If you’re signing a high-risk client contract or scaling subcontracting across projects, a contract review and properly drafted subcontract can save major time, cost, and stress later.

If you’d like help with a head contract, a subcontractor agreement, or aligning your project documents so you’re protected from day one, you can reach us at 0800 002 184 or team@sprintlaw.co.nz for a free, no-obligations chat.