Methodology
Every checker on this site is a deterministic rules engine over published data. No model guesses at your answer; the same inputs produce the same result every time, and the working is auditable.
Where the numbers come from
ACC classification rates are machine-extracted from the published Levy Guidebook PDFs (2024-25, 2025-26, 2026-27), audited by re-locating sampled units in the raw document, then spot-checked by hand before the file is marked verified. KiwiSaver and ESCT figures come from IRD's published guides; weekly compensation figures from ACC's published rates and the Accident Compensation Act 2001. Every data file carries its source URL and the date it was verified — and until a file is verified, the engine reaches its conclusion but refuses to show a figure. Stale data (past its validity date) gets the same treatment. Silent wrongness is the failure mode nobody would catch, so it is engineered out.
Order of operations
Disqualifying questions come before any dollar figure, always. An unanswered question is treated as unanswered — never as a "no". Arithmetic checks run before judgement checks. Where two answers both fit, the checker stops and says so; "ring ACC, it's free" is a result we are content to give.
The classification method
The checker never picks a code from a description directly. It classifies the situation into one of six archetypes, asks that archetype's fixed disqualifiers, and only then applies ACC's published highest-rate rule:
- Activity ceased entirely. You used to do the thing you are classified for. You have stopped doing it altogether.
- Activity now subcontracted out. The work still gets done under your name, but other businesses do it now, not your people.
- Moved up the chain (maker to designer, broker or wholesaler). You used to make it. Now you specify it, sell it, or arrange it, and somebody else makes it.
- Never right from the start. Nothing changed. The classification was wrong the day it was set, usually from a vague description on the original application.
- Shrank to office-only. The business is still trading but there is nobody on tools any more. It is an office now.
- Genuinely split activities. The business really does two or more different things, and it is all sitting under one classification.
Year-by-year comparisons use each year's own published rate. Part years are flagged, never apportioned — ACC apportions from its own records. Estimates are shown as a deliberately asymmetric band (0.75×–1.15×), and some findings carry no estimate at all because the number belongs to ACC's records, not ours.
What we cannot see
Your agency file, Experience Rating adjustments, employment agreements, IRD's processing queues. Each checker lists what it could not see on the result itself.
Auditability
The engine, its guardrails and its test gates are exercised before every deploy: twenty-two gates covering everything from "no number may exist in code" to "the ACC-bound letter must contain no dollar figure", plus a proof that every guard actually fires when its invariant is broken. The changelog records every data refresh.
Their words, and where you will see them
ACC, Inland Revenue and your council each have their own vocabulary, and we quote it exactly rather than paraphrasing — when you have an invoice in your hand you are matching what is on this screen against what is printed on that one. What no official page tells you is which part of the document to look at, so that is here too.
Classification Unit (CU)
ACC
In plain words: the five-digit code for what ACC thinks your business does
Where you will see it: On the levy invoice, near the top, under a heading that says "Classification unit". Five digits.
It sets the rate. Every dollar of the levy follows from this one number, and it does not update itself when the business changes.
Liable earnings
ACC
In plain words: the income figure the levy is charged on
Where you will see it: On the levy invoice, as the amount the calculation is applied to.
A wrong figure here scales everything else. Redundancy and retirement payments being included is a common reason it is too high.
Experience Rating
ACC
In plain words: a discount or loading on your levy based on your own claims history
Where you will see it: On the invoice as an adjustment line, if it applies to you.
If you are in it, the published rate for your classification is not your actual rate — so comparing published rates would give the wrong answer. That is why we ask.
ESCT — Employer Superannuation Contribution Tax
Inland Revenue
In plain words: the tax your employer pays on the KiwiSaver contribution they make for you
Where you will see it: On your payslip, if it is itemised at all. Plenty of payslips do not show it, which is not a problem — leave it blank.
The band is set by last year's salary plus contributions, not this year's, so a raise does not move it until the following year. Getting the year wrong is the most common mistake in this check.
PAYE — Pay As You Earn
Inland Revenue
In plain words: tax taken out of your wages before you are paid
Where you will see it: On every payslip, as a deduction line.
If tax came out of your pay, there may be a refund waiting when you leave the country part way through a tax year.
Gross earnings
Inland Revenue and payroll generally
In plain words: your pay before anything is taken out
Where you will see it: Top of the payslip, usually the largest number on it.
Almost every check here starts from gross, and people commonly enter what landed in their account instead.
YTD — year to date
payroll generally
In plain words: the running total since the tax year began on 1 April
Where you will see it: A separate column on the payslip, usually to the right of the amounts for this pay.
Comparing the year-to-date figures against the provider statement is what shows whether the contributions actually arrived.
Total remuneration
employment agreements
In plain words: a contract where the employer KiwiSaver contribution comes out of your stated salary rather than sitting on top of it
Where you will see it: In your employment agreement, in the pay clause.
It changes what the employer legally has to add, so answering it wrongly changes the whole KiwiSaver verdict.
Weekly compensation
ACC
In plain words: the weekly payment while you cannot work because of an injury
Where you will see it: On the ACC letter setting out your entitlement, and on each payment advice.
It is a published percentage of pre-injury earnings with a published weekly maximum. Both numbers are public, which is exactly why it can be checked.
Abatement
ACC
In plain words: the reduction in your weekly payment when you are also earning
Where you will see it: On the payment advice, as a reduction.
Doing a few hours of light duties changes what you should be paid. It is not a penalty and not a reason to stay off work — but it should be arithmetic you can see.
Statutory declaration
Oaths and Declarations Act 1957
In plain words: a short written statement you sign in front of somebody authorised to witness it
Where you will see it: Required by your KiwiSaver provider on their emigration withdrawal form.
Overseas it can be witnessed by a notary public or a Commonwealth representative, so being out of New Zealand is not a barrier. Usually a small fee and about fifteen minutes.
Labour Inspectorate
MBIE
In plain words: the free government team that investigates unpaid wages and holiday pay
Where you will see it: Complaints go through gethelp.employment.govt.nz.
It is free, it works from overseas, and it covers both the money owed and the employer failing to keep records.
myIR
Inland Revenue
In plain words: Inland Revenue's online account, at ird.govt.nz
Where you will see it: You register with your IRD number. It works from overseas.
Donation credits and part-year refunds are both claimed through it — and we never ask for the login.
Donation tax credit
Inland Revenue
In plain words: a third of what you gave, back from IRD
Where you will see it: Claimed in myIR. The receipt itself usually says "donation tax credit" on it.
The window is four years and rolling, so the oldest year expires every 31 March whether or not anybody claimed it.
Rates rebate
Department of Internal Affairs, paid through your council
In plain words: money off your rates bill when your income is under the threshold
Where you will see it: Applied for at your own council, on the official application form.
Assessed on last tax year's household income, and the deadline is a hard 30 June with no backdating.