NZ Tradie Variations, CCA Payment Claims & Retentions Guide (2026–2027)

Short answer: Under New Zealand tradie variation and retentions laws for 2026–2027—specifically the Construction Contracts Act 2002 (CCA), the Building Act 2004 ($30,000 mandatory residential contract rule), and the Construction Contracts (Retention Money) Amendment Act 2023—every scope change should be approved in a written Variation before work starts, every progress invoice should be served with a CCA Form 1 notice, and any retention money withheld must be held in a separate trust account.

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For New Zealand builders, sparkies, plumbers, roofers, drainlayers, and gib-stoppers, cash flow on a project comes down to three statutory protections that every tradie needs in their toolkit across 2026 and 2027:

1. Written Variations under the Building Act 2004 (and Part 4A for residential work $\ge$ $30,000 incl. GST) so homeowners cannot refuse to pay for site extras at handover;
2. Construction Contracts Act 2002 (CCA) Section 20 Payment Claims (accompanied by Form 1), which force the payer to either pay in full or serve a formal Payment Schedule within 20 working days (or the shorter time set in your contract); and
3. Strict Retention Money Trust Rules, which make it a criminal offence (fines up to $200,000 for companies / $50,000 for directors) for a head contractor or developer to mix your retention money with their working capital!

This guide shows how to use all three rules in 2026–2027, alongside our NZ quote template and NZ invoice template.

When is a written building contract and disclosure checklist mandatory in New Zealand?

Under Part 4A of the Building Act 2004 and the Building (Residential Consumer Rights and Remedies) Regulations 2014 administered by MBIE, a residential building contractor must provide a written contract, the mandatory MBIE Consumer Protection Checklist, and written disclosure of their skills, qualifications, LBP (Licensed Building Practitioner) status, and insurance before work begins whenever:

• The residential building work is priced at $30,000 or more (including 15% GST), or
• The homeowner asks for a written contract at any dollar value.

Failing to provide a compliant written contract or the MBIE disclosure checklist on a $30,000+ residential job carries an instant infringement fine from MBIE and leaves the implied default clauses of the Regulations governing your payment stages and variations! Even on jobs under $30,000, using a clear written quote with an explicit Variation Clause and CCA Payment Claim schedule is the single best way to avoid Disputes Tribunal arguments.

How should a Kiwi tradie document and price a Variation on site?

Never carry out extra work—moving a vanity waste pipe, adding soffit lighting, upgrading decking timber from H3.2 pine to Kwila, or digging out soft clay—on a verbal “yeah mate, chuck it on the bill.” Under standard NZS 3902 / Master Builders / Certified Builders contracts and the Consumer Guarantees Act 1993:

Variation Step on a New Zealand Jobsite	What to Include in Your Written Variation (VAR-01)	Why It Stops Disputes at Handover
1. Number & Reference the Original Quote	Variation #VAR-02 to Quote #Q-2026-084 (18 Kauri Rd Reno)	Keeps variations separate from the base fixed price
2. Describe the Scope Change & Reason	Owner instruction: Upgrade 12 × standard power points to brushed stainless with USB-C fast charge OR Unforeseen rotten bottom plate uncovered after lining removal	Proves the extra was not part of the original quoted scope
3. State the Price (Ex-GST, 15% GST, Total Incl. GST)	Materials: $420.00 + Labour (3 hrs @ $115): $345.00 = $765.00 + 15% GST ($114.75) = $879.75	Fixes the exact GST-inclusive figure in advance
4. State the Time Extension	Adds 1 working day to practical completion date	Prevents liquidated damages or delay complaints
5. Get Written Approval Before Starting	Client replies "Approved" by SMS, email, or signed PDF; billed on the next Progress Payment Claim	Satisfies written variation clauses

How do Construction Contracts Act 2002 (CCA) Payment Claims & Payment Schedules work?

The Construction Contracts Act 2002 (CCA) applies to every construction contract in New Zealand—both commercial and residential, and whether written or oral! However, there is a massive difference between sending an ordinary invoice and serving a valid Section 20 CCA Payment Claim:

Mandatory Checklist for a Valid NZ CCA Payment Claim (Section 20):

To trigger the strict statutory “sudden-death” payment rules of the CCA, your invoice must:

1. Be in writing;
2. Identify the construction work and the relevant period to which the payment relates;
3. Indicate the claimed amount and the due date for payment;
4. Indicate the manner in which the payee calculated the claimed amount;
5. State that the payment claim is made under the Construction Contracts Act 2002; AND
6. Be accompanied by the prescribed Form 1 (Information that must accompany all payment claims) from Schedule 1 of the Construction Contracts Regulations 2003, which outlines the payer’s legal obligations and the consequences of not responding!

Step in the CCA Payment Process	Statutory Default Timeline (Unless Contract Sets Shorter Time)	What Happens If the Payer Misses the Deadline?
1. You serve a valid CCA Payment Claim + Form 1	At the end of each monthly construction period (or contract milestone)	Clock starts ticking on the date of service
2. Payer must pay in full OR serve a written “Payment Schedule” (Section 21)	Within 20 working days after the Payment Claim is served (many contracts shorten this to 10 or 12 working days)	If no valid Payment Schedule is served in time, the entire claimed amount becomes a statutory debt due (Section 22)
3. Due date for payment passes with no payment (Section 23 & 24A)	Payer fails to pay the claimed amount (or scheduled amount) by the due date	You can recover the full debt in the District/High Court with actual reasonable legal costs, refer to CCA Adjudication, AND suspend work after giving 5 working days’ written notice!

Read that again: if you attach CCA Form 1 to your progress invoice and state that it is a Payment Claim under the Construction Contracts Act 2002, a homeowner or head contractor who ignores it for 20 working days without serving a formal written Payment Schedule loses the legal right to dispute the amount of that progress claim!

How do New Zealand’s strict Retention Money Trust rules protect subcontractors in 2026–2027?

On commercial subcontracts in New Zealand, head contractors commonly deduct retentions (typically 10% on the first $200,000, scaling down to 5% total, with half released at Practical Completion and the remaining half at the end of the 3-to-12-month Defects Liability Period).

Under the Construction Contracts (Retention Money) Amendment Act 2023 (in full force across 2026 and 2027), if a head contractor or commercial client withholds retention money from your payment claim:

1. Deemed Statutory Trust at the Moment of Deduction: The retention money is automatically deemed to be held on trust for you the instant it is withheld—whether or not the head contractor actually moved cash!
2. Mandatory Separate Bank Account (or Complying Instrument): The retention money must be deposited into a separate New Zealand bank trust account used solely for retention money (it cannot be mixed with the head contractor’s general overdraft or working capital).
3. Mandatory Reporting Every 3 Months: The party holding your retentions must give you a written statement at least once every 3 months (and immediately when each retention is withheld) stating the exact amount withheld, the date, the total held for you, and the specific bank account name and number where your trust money sits!
4. GST timing on NZ retentions: Under Section 9(3) of the Goods and Services Tax Act 1985 and IRD guidance, if you account for GST on the Payments basis, you only return 15% GST as you actually receive cash; if you are on the Invoice basis, review whether the retention is billed on a separate retention release invoice or part of the initial progress tax supply.

When can a New Zealand tradie legally suspend work on site for non-payment?

Under Section 24A of the Construction Contracts Act 2002, if a payer fails to pay the claimed amount (where no Payment Schedule was served in time) or the scheduled amount by the due date, you have the statutory right to suspend construction work after serving a written Notice of Intention to Suspend Work and waiting 5 working days without receiving payment in full.

Frequently asked questions

When do I legally need a written building contract in New Zealand?

Under Part 4A of the Building Act 2004, a written contract, the MBIE Consumer Protection Checklist, and written disclosure information must be provided before work begins on any residential building project costing $30,000 or more (including 15% GST), or whenever the homeowner requests a written contract regardless of the price.

Why must I attach CCA Form 1 to my New Zealand progress invoices?

Under Section 20(3) of the Construction Contracts Act 2002, a progress invoice for construction work (whether residential or commercial) is only a valid statutory Payment Claim if it is accompanied by the prescribed Form 1 notice from the Construction Contracts Regulations 2003. Without Form 1 attached, you cannot enforce the 20-working-day “pay or serve a Payment Schedule” default rule or use the statutory right to suspend work.

How many days notice must a Kiwi tradie give before suspending work for non-payment?

Under Section 24A of the Construction Contracts Act 2002, if a claimed amount (where no Payment Schedule was served) or a scheduled amount is not paid by the due date, you may suspend construction work after serving a written Notice of Intention to Suspend Work and waiting 5 working days without receiving payment.

How can I check that a head contractor is actually holding my retentions in a trust account?

Under the Construction Contracts (Retention Money) Amendment Act 2023, the head contractor is legally required to report to you in writing as soon as retention money is withheld and at least once every 3 months thereafter, specifying the exact dollar amount held and the bank and account details of the dedicated retention money trust account. You also have the statutory right to inspect the retention trust records free of charge.

Can a client withhold 100% of my final invoice over a minor $200 defect?

No. If you serve a valid CCA Payment Claim (with Form 1), a client who wants to withhold money for an alleged defect must serve a written Payment Schedule within the statutory timeframe stating the exact lesser “scheduled amount” they propose to pay, how they calculated the deduction for the defect, and their detailed reasons—and they must still pay the undisputed scheduled balance by the due date.

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This article is general construction and legal information, not formal legal advice. Consult Building Performance (building.govt.nz), Inland Revenue, or a New Zealand construction lawyer.

Send numbered NZ quotes, lock in written Variations, and track CCA Payment Claims and retentions on-device with Keel on the App Store.