A contractor invoice in New Zealand is the commercial document that ties your agreed scope, milestones, and purchase order data to the dollars a payer will release, whether you trade as an individual, partnership, trust, or company. When your engagement is a schedular payment, Inland Revenue expects the payer to withhold tax using the rate on your completed IR330C form, and if you do not supply that form the payer must deduct at the forty-five percent non-notified rate for most cases or twenty percent when the contractor is a non-resident company. You still need to register for GST when IRD registration tests are met, including the schedular-specific note that you must register if you earn sixty thousand dollars a year or more before expenses from schedular payments or if you add GST onto your prices. Once GST registered, your taxable supplies need taxable supply information that satisfies IRD tier rules, including buyer identifiers on higher value supplies. Many contractors also show a New Zealand Business Number so enterprise accounts payable can match vendor records. This guide summarises public IRD and New Zealand Government guidance only and is not tax or legal advice.
At February 2024, Stats NZ reported that seventy-three percent of enterprises in New Zealand did not have any paid employees, which captures how many micro and lean contracting firms depend on disciplined invoicing to keep cash flow steady (Stats NZ, New Zealand business demography statistics: At February 2024, 2024). Allan Bullot, partner at Deloitte, told RNZ in 2024 that with tools such as Xero and MYOB, doing GST has become much simpler for many firms, which is why compliance debate often focuses on thresholds and behaviour rather than paper titles alone (RNZ, Small businesses restrict sales to avoid GST, 2024).
What makes contractor invoices different from a simple one-off bill?
Contractor work usually carries purchase orders, labour-hire chains, schedular withholding, and sometimes retention or progress claims, so your invoice has to satisfy both commercial matching rules and IRD identity and GST rules. The points below join IR330C habits, payer obligations, and taxable supply information expectations.
01
Who can receive schedular payments and why does that change your paperwork?
IRD explains that contractors doing certain activities or services, or contractors working in certain industries, where the supply mainly consists of labour, can receive schedular payments, and that a contractor can be an individual, partnership, trust, or company (Inland Revenue, About schedular payments for contractors, last updated 20 May 2025). Your invoice or statement should make it obvious which entity earned the payment so payers withhold against the correct IRD number.
02
What happens if you do not give the payer a completed IR330C form?
IRD states that if the contractor does not give you an IR330C form, you need to deduct tax at either twenty percent if the contractor is a non-resident company or the forty-five percent non-notified rate, then pay those deductions to Inland Revenue (Inland Revenue, Deductions from payments to contractors, last updated 16 Apr 2026). That is why contractors should hand over IR330C before the first pay run rather than after accounts payable closes.
03
How do payers calculate withholding once they have your rate?
IRD instructs payers to multiply the contractor tax rate by the gross payment to find the tax to withhold, and reminds them that they do not need to deduct student loan repayments, KiwiSaver deductions, or ACC levies from schedular payments (Inland Revenue, Tax schedular payments and file employment information, last updated 1 Apr 2026). Your invoice should still show gross fees clearly so everyone can reconcile to the cash that hit the bank.
04
When must a contractor still register for GST on top of withholding?
IRD states you need to register for GST if you earn sixty thousand dollars a year or more before expenses from your schedular payments, or if you add GST onto your prices, and points to broader GST guidance for what that means in practice (Inland Revenue, About schedular payments for contractors, last updated 20 May 2025). Voluntary registration below the threshold remains possible when you have a taxable activity story IRD accepts.
05
Why do tiered taxable supply rules still matter on large milestone invoices?
IRD taxable supply information rules decide how much buyer detail you show at two hundred dollars, between two hundred and one thousand dollars, and above one thousand dollars for GST-registered buyers, including the twenty-eight day response window on many requests (Inland Revenue, How taxable supply information for GST works, last updated 31 Mar 2026). Construction and IT milestone bills often cross those thresholds in a single line.
Sources
What official sources stress about contractor payments
These points come from Inland Revenue schedular guidance and Stats NZ business demography releases. They anchor templates in facts rather than offshore blog defaults.
IRD states that contractors who receive schedular payments must give payers a completed Tax rate notification for contractors IR330C form, otherwise payers must deduct at twenty percent for non-resident companies or the forty-five percent non-notified rate (Inland Revenue, Deductions from payments to contractors).
Inland Revenue, Deductions from payments to contractors (2026). View source
Stats NZ reported that at February 2024 seventy-three percent of enterprises in New Zealand did not have any paid employees, illustrating how many lean contracting entities rely on clear payment documentation (Stats NZ, New Zealand business demography statistics: At February 2024, 2024).
Stats NZ, New Zealand business demography statistics: At February 2024 (2024). View source
Workflow
How do you invoice as a contractor from engagement to lodged returns?
Confirm who is contracting, align schedular paperwork, track GST tests, mirror commercial references, then archive evidence for seven years.
1
Lock the contracting entity, trading name, IRD number, bank account, and NZBN
Match the name on your contract, labour-hire agreement, or purchase order to the entity that will appear on the invoice. Update IRD contact details through myIR when addresses change, and show your NZBN when you have one so buyers can reconcile vendor master data (business.govt.nz, New Zealand Business Number).
2
Complete IR330C and agree gross fees versus schedular withholding with the payer
Give payers the IR330C rate Inland Revenue expects for your activity, renew tailored tax certificates before they expire, and keep copies of what you supplied so you can explain differences between gross invoices and net deposits (Inland Revenue, About schedular payments for contractors; Inland Revenue, Deductions from payments to contractors).
3
Track GST registration triggers including schedular turnover guidance
Compare rolling income against IRD registration tests, remembering IRD states you must register when you earn sixty thousand dollars a year or more before expenses from schedular payments or when you add GST to prices (Inland Revenue, About schedular payments for contractors; Inland Revenue, Registering for GST, last updated 13 Feb 2025).
4
Carry purchase orders, job codes, milestones, and retention wording into the invoice body
Mirror the references your payer uses in their enterprise resource planning system so three-way matching between order, delivery evidence, and invoice does not stall in a shared inbox.
5
Pick document wording that matches GST registration and each supply
If you are not GST registered, avoid GST line items that imply you collected GST. Once registered, issue taxable supply information that satisfies IRD tier rules for each supply value, still using the words tax invoice when that fits your workflow (Inland Revenue, Taxable supply information for GST; Inland Revenue, How taxable supply information for GST works).
6
Number the invoice, describe labour and materials separately when it helps, and show New Zealand dollars clearly
Follow Invoice Mama's New Zealand tax invoice guide for tiered fields, including buyer identifiers above one thousand dollars and the twenty-eight day response expectation for GST-registered buyers on supplies over two hundred dollars (Inland Revenue, How taxable supply information for GST works).
7
File income tax and GST obligations, then store PDFs, IR330C copies, and bank confirmations for seven years
Reconcile schedular statements to tax returns with your accountant, meet GST return frequency deadlines, and retain issued and received documents for seven years as IRD describes for income and expense records (Inland Revenue, Records of income and expenses, last updated 1 Apr 2023).
Checklists
Checklists: contractor invoices before you send the PDF
Use this list right before delivery. It joins schedular payer habits with IRD identity and GST expectations.
Entity and payer matching
The legal name and IRD number on the invoice match the entity named on the contract and IR330C
Purchase order numbers, job codes, and milestone labels mirror what the payer approved
Corporate buyers see the NZBN you quoted during onboarding when you have one
Commercial clarity
Invoice numbers stay unique and dates reflect the supply story you intend
Line descriptions tie to approved scope so disputes cannot hide behind vagueness
Payment terms, due dates, and retention references follow your written agreement
If you are GST registered
Taxable supply information satisfies IRD tier rules for each supply amount, including buyer GST numbers and identifiers above one thousand dollars when required (Inland Revenue, How taxable supply information for GST works)
GST return periods label the folder where PDFs, schedular remittances, and bank confirmations live
Credit or debit adjustments reference IRD supply correction guidance when mistakes surface (Inland Revenue, Taxable supply information for GST)
Pitfalls
What trips up contractors on New Zealand invoices?
The expensive habits are mismatched entity names, missing IR330C leading to forty-five percent withholding, charging GST without registration, and weak buyer identifiers on large taxable supplies.
You invoice under a different entity than the one on IR330C
Problem
Payers map withholding to the IRD number on your notification. If the invoice names another partnership or company, payment runs and GST credits can stall while finance teams investigate.
Fix
Issue credit or replacement documents with matching labels, then update labour-hire and procurement portals in the same session.
You skip IR330C because you think invoices replace the form
Problem
IRD requires the completed IR330C for payers to use declared rates instead of the forty-five percent non-notified default in most cases (Inland Revenue, Deductions from payments to contractors).
Fix
Send IR330C with your first invoice pack, then resend whenever tailored certificates renew.
You show fifteen percent GST while IRD has not confirmed registration
Problem
IRD ties lawful GST collection to registration status and taxable supplies. Charging GST early can create rework with buyers and registration timing questions (Inland Revenue, Registering for GST).
Fix
Issue non-GST invoices until your effective registered date is clear, then reissue corrected taxable supply information if quotes shifted.
You omit buyer identifiers on supplies over one thousand dollars
Problem
IRD requires buyer name or trade name, GST number, and identifier detail for supplies over one thousand dollars to GST-registered buyers, otherwise their GST credit evidence fails (Inland Revenue, How taxable supply information for GST works).
Fix
Validate buyer GST numbers and at least one identifier field before you email large milestone invoices.
Frequently asked questions
Contractors who bill head contractors, agencies, councils, and corporates, and need paperwork accepted on first pass.
Does schedular withholding replace GST on the same payment?
No. Schedular payments deal with income tax withholding at the payer, while GST is a separate consumption tax story when you are registered. Your invoice still needs to show GST correctly on taxable supplies, and your bank feed will show both withheld tax and GST collected or paid depending on your setup.
What gross amount should appear on the invoice when payers withhold tax?
Show the agreed professional fee or contract rate as the gross charged for the service. Withholding sits on the payer side, so your narrative should still let finance teams reconcile gross, withheld tax, and net cash without guessing.
How quickly must payers file employment information after a schedular payment?
IRD states you need to file the employment information within two working days of the date of payment if filing electronically, or within ten working days if filing by paper (Inland Revenue, Tax schedular payments and file employment information).
Can a company director use the same contractor invoicing checklist?
Yes when the company is the entity contracting and IRD recognises schedular payments for directors fees in their examples list. Keep director fee invoices inside the company letterhead and IRD numbers your board agreed.
Is a New Zealand Business Number mandatory on contractor invoices?
IRD taxable supply tiers focus on GST numbers and descriptive fields rather than mandating NZBN on every document, yet enterprise procurements increasingly expect NZBN data for vendor matching (business.govt.nz, New Zealand Business Number). Treat NZBN as best practice when you have one.
How soon must I give taxable supply information after a GST buyer asks?
IRD explains that for supplies over two hundred dollars you must provide taxable supply information within twenty-eight days of a request unless another date is agreed (Inland Revenue, How taxable supply information for GST works, last updated 31 Mar 2026).
Where should I read IRD field lists beside this overview?
Open Invoice Mama's guides on what to include on a New Zealand tax invoice and taxable supply information, then read how to register for GST in New Zealand when turnover tests are close.
What reminder cadence helps after invoices age past due?
Invoice Mama's unpaid invoice follow-up guide walks through factual reminders, documentation, and escalation patterns once balances sit past due.
Keep learning
Related guides
Layer IRD registration guidance with field-by-field taxable supply rules, then add collections habits.
Send contractor invoices that match IR330C, GST, and buyer systems
Invoice Mama helps you issue branded invoices, keep sequential numbering, and show payment terms while you move between schedular payment statements, GST-registered taxable supply information, and IRD record keeping.