Buyer-Created Tax Invoices (BCTIs) In New Zealand

If you run a small business, invoicing sounds straightforward - the supplier sends the invoice, you pay it, and everyone moves on.

But in some industries, it’s actually more practical (and sometimes expected) for the buyer to generate the invoice on behalf of the supplier. That’s where buyer created tax invoices (BCTIs) come in.

Used properly, BCTIs can speed up payments, reduce disputes over quantities or pricing, and make your accounts team’s life a whole lot easier. Used poorly, they can create messy record-keeping and compliance issues - especially around GST information and “who said what” if there’s a disagreement later.

Below, we’ll break down what buyer created tax invoices are in New Zealand, when they’re appropriate, the key contracting and GST record considerations, and how to set up a practical BCTI process that protects your business from day one. (This article is general information only and isn’t tax advice - for GST treatment in your specific situation, talk to your accountant or Inland Revenue.)

What Are Buyer Created Tax Invoices (BCTIs)?

A buyer created tax invoice is an invoice (or GST record) that the buyer prepares, rather than the supplier.

In practice, it usually happens when:

• the buyer is best placed to calculate the final amount payable (for example, based on weights, grades, meter readings, hours verified, or outputs accepted); and
• the supplier is happy to let the buyer issue the invoice to avoid delays and back-and-forth.

You might also hear this called “self-billing” in other countries. In New Zealand, the term “buyer created tax invoice” is still commonly used, particularly where the parties want the buyer’s document to serve as the key GST record for the transaction.

Important note on terminology: New Zealand’s GST rules changed from 1 April 2023, and the concept of a “tax invoice” has largely been replaced with taxable supply information. However, many businesses (and accounting systems) still use the language of “tax invoices”, and the practical compliance goal is the same: ensuring you have the right information on record to support your GST position.

The key takeaway is that a BCTI is about the buyer issuing a document (or set of records) that contains the required supply details, so both parties can rely on it for their GST and accounting records.

When Do BCTIs Make Sense For Small Businesses?

Buyer created tax invoices aren’t for every business relationship. They’re most useful where the buyer controls the “final numbers” and wants consistency across payments.

Common situations where buyer created tax invoices can make sense include:

• Primary industries: produce, livestock, dairy, forestry, fishing, and other volume/grade-based purchasing.
• Labour or contracting arrangements: where the buyer verifies time sheets or job completion and then issues the invoice based on approved hours or milestones.
• Commission or incentive payments: where the buyer calculates commission owing (for example, based on sales figures they control).
• Aggregators and marketplaces: where the platform/buyer collects end-customer payments and needs to generate supplier payment records.

From a practical standpoint, BCTIs are attractive because they can:

• reduce disputes over quantities and rates (because you’re invoicing based on what you actually accept/measure);
• make payment cycles faster (no waiting on suppliers to issue invoices); and
• standardise documentation (useful when you deal with lots of small suppliers).

That said, the buyer is taking on extra responsibility. If your BCTI process is sloppy, you can end up with GST documentation gaps, supplier complaints, or misunderstandings about whether the supplier has “approved” your calculations.

What Does New Zealand Law Require For BCTIs And GST Records?

When people talk about buyer created tax invoices, the underlying issue is usually: will this document (and the surrounding records) support our GST position if Inland Revenue ever asks questions?

In New Zealand, GST is governed by the Goods and Services Tax Act 1985. The rules about invoicing and evidence for GST claims have been modernised, and many businesses now focus on ensuring they hold the correct taxable supply information rather than relying on a strictly formatted “tax invoice”.

For small businesses, the practical compliance points typically come down to this:

• You need clear evidence of the supply (what was supplied, when, and by whom).
• You need the value and GST treatment (how much, whether GST applies, and the GST amount if applicable).
• You need to correctly identify the parties (buyer and supplier details, including GST numbers where relevant).
• You need proper record-keeping so you can support your GST returns if you’re ever reviewed.

With BCTIs, an extra layer is that the buyer is preparing the document, so it’s even more important that the arrangement is agreed and the information is accurate.

Do Both Parties Need To Be GST-Registered?

Not always - but it matters.

• If the supplier is GST-registered and the supply is taxable, the documentation needs to support GST being charged and claimed correctly.
• If the supplier is not GST-registered, they generally should not be charging GST, and your BCTI should not incorrectly show GST as if it applies.

This is one of the biggest risk areas we see: buyers generating “tax invoice-looking” documents that suggest GST is included when the supplier isn’t registered (or shouldn’t be charging GST). That can create problems for both sides.

What Information Should A Buyer Created Tax Invoice Include?

Your BCTI (or taxable supply record) should be consistent and contain the core details you’d expect for a GST support document. In plain English, aim to include:

• the words “Buyer Created Tax Invoice” (so it’s obvious what it is);
• your business name and contact details;
• the supplier’s legal name and contact details;
• each party’s GST number (if applicable);
• the date of issue;
• a clear description of what you’re paying for (goods/services);
• quantity/units and rate (if relevant);
• the total amount payable;
• whether GST is included, added, or not applicable; and
• any references that help reconcile the transaction (purchase order numbers, delivery docket numbers, job IDs, contract references, etc.).

If you’re unsure what you need for your specific setup (for example, mixed supplies, zero-rated supplies, or cross-border elements), it’s worth getting tailored advice from your accountant or tax adviser before rolling out a BCTI process at scale.

Why You Need A BCTI Agreement (And What To Put In It)

In most cases, the difference between a clean BCTI arrangement and a stressful one is simple: having the right agreement in place upfront.

Even if the GST record-keeping side is your initial motivation, the commercial reality is that BCTIs change the usual dynamic. The supplier is letting you:

• calculate what they’re owed; and
• issue the invoice document that they’ll rely on for their own records.

That only works smoothly when the rules are clear.

Depending on your relationship, your BCTI terms might sit inside a broader Service Agreement, a Supply Agreement, or your Terms of Trade.

Key Clauses To Include In A BCTI Agreement

Every business is different, but a solid BCTI arrangement often covers:

• Authority to issue invoices: confirmation that you (the buyer) are authorised to create invoices on the supplier’s behalf for specified supplies.
• When BCTIs apply: define the products/services covered, and whether any exceptions apply.
• Pricing and calculation method: rates, grade tables, measurement methods, rounding rules, deductions, set-offs, and any adjustments (like rejects, wastage, or rework).
• GST status warranties: whether the supplier is GST-registered, and an obligation to tell you if that changes.
• Supplier review and dispute process: how long they have to query an invoice, how disputes are handled, and what happens to payment timing during disputes.
• Records and retention: who keeps what records, for how long, and in what form.
• No duplicate invoicing: the supplier agrees not to also issue invoices for the same supplies (to avoid double-accounting confusion).

If you’re dealing with many suppliers, you might also want a standard onboarding process where suppliers sign an authority/acceptance form before you issue the first buyer created tax invoice.

And if your BCTI arrangements sit inside a bigger set of commercial terms, it can be worth getting a lawyer to review the full structure - not just the invoice template - so it all aligns (especially around payment terms, liability, and termination).

How To Set Up A Practical BCTI Process (Step By Step)

Once you’ve decided that buyer created tax invoices are right for your business model, your next job is making the process consistent and audit-ready.

Here’s a practical step-by-step approach.

1. Confirm The Commercial Reason You Need BCTIs

Be clear internally why you’re doing this. Examples include:

• you determine the final payable quantity (weights/grades/meter readings);
• you approve hours/milestones; or
• you need uniform documentation across many suppliers.

This matters because if a supplier later challenges the arrangement, you’ll want to point to a clear operational justification (not just “we prefer it this way”).

2. Verify Supplier Details Before You Start

At onboarding, collect and confirm:

• legal name and trading name (if different);
• NZBN (if applicable);
• address and contact details;
• bank account details; and
• GST registration status and GST number (if registered).

Because you’re handling their invoicing records, you’ll likely be collecting personal information (like a sole trader’s bank details). Make sure your Privacy Policy and internal practices match the Privacy Act 2020 expectations around collection, storage, and access.

3. Put The Agreement In Place (And Keep It Accessible)

Don’t rely on a casual email chain.

Get a signed agreement (or at least a clear written acceptance process) before issuing buyer created tax invoices. If you ever have to prove authority to issue invoices, this document is your safety net.

4. Standardise Your BCTI Template

Use one template across the business, and lock down who can edit it.

A good template should:

• clearly label the document as a buyer created tax invoice;
• contain the required GST and supply details; and
• include references back to source data (dockets, timesheets, purchase orders).

5. Build In Controls (So You Don’t Create Your Own Dispute)

Because the buyer is issuing the invoice, you should assume suppliers will scrutinise them closely - especially if deductions or adjustments are involved.

Practical controls include:

• approval workflows for quantities, rates, and deductions;
• version control for pricing schedules;
• clear written reasons for adjustments (and supporting documents); and
• a supplier query window (for example, “raise any issues within X business days”).

These controls aren’t just “good admin” - they’re part of protecting your business relationship and reducing the chance of a payment dispute turning into a wider contract conflict.

Common Risks With Buyer Created Tax Invoices (And How To Avoid Them)

Buyer created tax invoices can be a huge win for efficiency, but there are a few repeat problem areas we see for small businesses.

Risk 1: Incorrect GST Treatment

If you treat a supply as GST-inclusive when it isn’t (or vice versa), you can create tax issues for both parties.

How to avoid it: confirm supplier GST status at onboarding, include a “tell us if it changes” obligation in your agreement, and review GST coding in your accounting system with your accountant or bookkeeper.

Risk 2: Suppliers Also Issue Their Own Invoices

If the supplier issues their own invoices and you issue BCTIs as well, you can end up with duplicate records, payment confusion, and disputes about what’s actually owed.

How to avoid it: include a clear “no duplicate invoicing” clause and explain your process upfront so the supplier knows what to expect.

Risk 3: Disputes Over Deductions And Set-Offs

If you deduct charges (like damage, rejects, or penalties) without a clear contractual basis, suppliers may argue you had no right to do it.

How to avoid it: make sure your contract/terms clearly allow deductions and explain how they’re calculated. This is often handled cleanly in a well-drafted Terms of Trade style document or supply contract.

Risk 4: BCTIs Become Evidence In A Wider Contract Dispute

Invoices aren’t just accounting documents - they often become evidence of:

• what the parties agreed the price was,
• whether work was accepted, and
• payment timing and patterns.

How to avoid it: make sure your written agreement matches what you actually do in practice, and keep your invoice descriptions clear and consistent.

Risk 5: Cashflow And Credit Risk

Sometimes BCTIs sit inside arrangements where payments are made quickly against variable future amounts, or where the buyer is exposed to customer non-payment risk. If that’s part of your model, it’s worth thinking about what contractual protections you need around payment timing, disputes, and remedies if things go wrong.

Depending on the relationship, that may include stronger payment terms, enforcement rights, or (in some cases) security arrangements - but what’s appropriate is highly fact-specific, so it’s worth getting advice on the commercial contract structure.

Key Takeaways

• Buyer created tax invoices (BCTIs) are invoices created by the buyer on the supplier’s behalf, usually where the buyer controls the final calculation of what’s payable.
• BCTIs can improve speed and consistency, but they also shift responsibility to the buyer - so your process needs to be accurate and well-documented.
• New Zealand GST compliance focuses on having the right taxable supply information on record under the Goods and Services Tax Act 1985, even if you still use “tax invoice” language operationally.
• A written BCTI agreement is crucial to confirm authority to issue invoices, prevent duplicate invoicing, and set a clear dispute process.
• Common pitfalls include incorrect GST treatment, unclear deductions, and mismatched paperwork versus real-world practice - all of which can be avoided with clear contracts and good controls.

If you’d like help setting up the contract side of a BCTI process - including supplier agreements, terms, and a practical dispute framework - you can reach us at 0800 002 184 or team@sprintlaw.co.nz for a free, no-obligations chat. For GST/tax questions specific to your circumstances, you should also speak with your accountant or Inland Revenue.