nz_schedular_payment_calculator
shallownz.co.calculate/calculator · Verify this server
Work out the withholding tax on a New Zealand schedular payment to a contractor, and what the contractor is actually left with. Use for: 'withholding tax on contractor payment', 'schedular payment tax rate', 'IR330C rate', 'director fee tax NZ', 'what tax do I deduct from a contractor', 'no IR330C what rate'. TWO RULES CAUSE MOST OF THE TROUBLE. WITHHOLDING TAX IS CHARGED ON THE PAYMENT EXCLUDING GST. A GST registered contractor invoicing $1,000 plus GST bills $1,150, and the withholding is charged on the $1,000. Charging it on the GST-inclusive figure over-deducts by 15% of the tax every single time, and it is a common payroll error. THE RATE DEPENDS ON THE ACTIVITY, NOT ON THE CONTRACTOR. Schedule 4 sets a standard rate per listed activity. A contractor may elect anything between 10% and 40% on an IR330C. WITHOUT THAT FORM THE PAYER MUST DEDUCT AT 45%, the no-notification rate, which is punitive by design and catches people who simply never sent the paperwork back. If someone is being deducted 45%, the fix is usually a form, not an argument. THE DEDUCTION IS NOT A FINAL TAX. It is a credit against the contractor's income tax for the year, so a contractor with deductible expenses usually gets some back and one with a large profit usually owes more. year_end_credit is the figure that goes in the return. Do not describe the deduction as "the tax they paid on that job". Args: payment_excluding_gst: The fee BEFORE GST. activity: Schedule 4 activity, which sets the standard rate. rate_option: standard, nominated (an IR330C election), or no_form. nominated_rate_pct: The elected rate, 10 to 40. Required for nominated. gst_registered: Whether the contractor is GST registered. Returns: The invoice, the rate and why it applies, the tax deducted, the net to the contractor, and the credit claimable at year end.
1 trials · measured 27 days ago
nz_schedular_payment_calculator scores 100.0/100 on Vouch's measured behaviour index, from 1 real invocation trials against nz.co.calculate/calculator, measured 11 Sept 2026 under methodology v0.2.0. Every measured component scored 100.
Component breakdown
| Component | Weight | Value |
|---|---|---|
| Reliability | 35% | not applicable |
| Schema integrity | 25% | 100.0 |
| Failure behaviour | 15% | not applicable |
| Latency | 15% | not applicable |
| Concurrency | 10% | not applicable |
Tool details
- Transport
- remote
- Credential class
- self-provisionable
- Input schema
- not declared
- Output schema
- not declared
- Side-effect classification
- unclassified
Score history
| Day | Score | Tier | Methodology |
|---|---|---|---|
| 2026-09-11 | 100.0 | shallow | v0.2.0 |
Probe evidence
| Probe | Outcomes |
|---|---|
| schema_integrity | pass: 1 |
Raw request/response logs are not archived yet — the outcome counts above are drawn directly from every recorded trial.
Embed this score
Available for every tool, scored or not — not a verification perk. Always links back to this page.
[](https://vouch.tools/tools/ea7b152b-9a6d-4c9c-a2ef-5c1d851bf699)