Why Is My ACC Invoice So High? What Self-Employed NZers Need to Know

Every July and August, the same thing happens. ACC invoices land in inboxes across New Zealand, and the reaction is almost always the same: that can't be right.

If you are self-employed, a sole trader, or running a small company, your ACC invoice can feel disproportionately large — especially if you have never had a claim and have been paying for years without incident. This article explains exactly why the invoice is what it is, how ACC calculates your levies, and what options you have if you think you are being overcharged.

ACC — the Accident Compensation Corporation — is New Zealand's no-fault personal injury scheme. It covers treatment and lost income if you are injured, whether at work, at home, or anywhere else. In exchange, you give up the right to sue for personal injury.

For employees, ACC levies are largely invisible — they are deducted from wages as part of PAYE. For self-employed people and business owners, the invoice arrives directly, which is why it tends to feel more confronting.

There are three separate levies that make up your ACC bill:

This is the biggest component for most self-employed people. It is calculated as a percentage of your liable earnings (your income up to the maximum threshold, which is $142,283 for the 2025–2026 year).

The percentage depends on your classification unit — essentially, what type of work ACC considers you to do. Classifications range from very low risk (office-based work) to very high risk (forestry, fishing, construction). If you are classified in the wrong category, you could be paying a rate that does not reflect your actual work.

This is a flat rate applied to all earners in New Zealand — employees and self-employed alike. For 2025–2026 it is $1.39 per $100 of liable earnings. It funds non-work injuries (injuries that happen outside of work).

A small flat levy that funds WorkSafe New Zealand. Currently $0.08 per $100 of liable earnings.

ACC uses your prior year's income (as filed with IRD) to calculate the levy. This means:

• If your income went up significantly last year, your levy will reflect that — and it may be higher than you expected
• If you had an unusually high-income year, you will pay levies on that income even if this year is quieter
• If you are newly self-employed, ACC will estimate your income and invoice you based on that estimate

The invoice you receive in July or August is typically based on the income you declared in your most recent tax return.

This is the most common cause of overpayment. ACC assigns you a classification unit based on your business description — but these classifications are not always accurate, and ACC does not proactively review them.

A tradie who does primarily supervisory or design work may be classified at a higher rate than their actual risk profile warrants. A consultant classified under a legacy industrial code may be paying rates that bear no resemblance to their desk-based work.

You can apply to have your classification reviewed. If ACC agrees, the change applies going forward — and in some cases, you may be entitled to a refund for prior years.

If your income jumped significantly in the year ACC is invoicing for, the levy will reflect that. There is not much you can do about this retrospectively, but it is worth understanding so you can plan for it in future years.

Occasionally, the income figure ACC uses does not match what you actually earned — particularly if there were amendments to your tax return, or if you have multiple income sources. It is worth checking the income figure on your invoice against your filed return.

Standard ACC cover for self-employed people is called CoverPlus. Under this, if you are injured and cannot work, ACC pays 80% of your prior year's income. The levy is calculated on your actual earnings.

CoverPlus Extra is an alternative that lets you agree a fixed level of cover with ACC — regardless of your actual income. This can be useful if:

• Your income fluctuates significantly year to year
• You want certainty about what you would receive if injured
• You want to reduce your levy by agreeing a lower (but still adequate) level of cover

CoverPlus Extra is not right for everyone, but it is worth understanding as an option.

Step 1: Check your classification unit

Your invoice will show your classification unit code. You can look this up on the ACC website to see whether it accurately reflects your work. If it does not, you can apply for a review.

Step 2: Check the income figure

Make sure the income ACC has used matches your filed tax return. If there is a discrepancy, contact ACC directly.

Step 3: Consider CoverPlus Extra

If your income is variable or you want more control over your levy, talk to an accountant about whether CoverPlus Extra makes sense for your situation.

Step 4: Talk to a registered tax agent

ACC levy reviews are not complicated, but they do require knowing what to look for. A registered tax agent or accountant who works with self-employed clients regularly will know the common misclassifications and how to challenge them.

If you operate through a company, the rules are slightly different. The company pays an employer levy on wages paid to employees (including shareholder-employees). You as a shareholder-employee also pay the earners' levy on your shareholder salary.

The work levy rate still depends on the classification unit — so the same misclassification risk applies.

ACC levies are not optional, and the scheme provides genuinely valuable cover. But the system is complex enough that overpayment is common — particularly for self-employed people and small business owners who have never had their classification reviewed.

If your invoice has arrived and the number looks wrong, do not just pay it and move on. Take ten minutes to check the classification and the income figure. If something looks off, it is worth pursuing.

If you would like a second opinion on your ACC classification or levy structure, get in touch with us. We work with self-employed clients and small business owners across New Zealand and review ACC levies as part of our standard advisory work.