NZ Trader Tax Guide 2026: How to Declare Trading Income on Your IR3

The short version

• NZ trading profits are ordinary income, taxed at your marginal rate — there's no separate capital gains rate.
• The current tax year runs 1 April 2025 – 31 March 2026, and the IR3 is due 7 July 2026 (later if you're with a tax agent).
• You declare net profit — gains minus losses, minus your deductible costs.
• Losses carry forward indefinitely against future profits.
• If you trade crypto, CARF reporting has begun, but IRD doesn't receive that data until 2027 — more on that below.

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Almost everything written about trading tax online is American. Capital gains rates, Schedule D, long-term versus short-term holding periods — none of it applies to you. Here's the New Zealand version, in language that won't put you to sleep.

Does IRD tax trading profits? Yes.

People get hung up on the fact that NZ has no broad capital gains tax and assume trading is tax-free. It isn't. The Income Tax Act catches trading income a few different ways — if you trade systematically and for profit it's business income; if you bought something intending to resell it at a gain, that gain is taxable; and forex, CFDs and futures are "financial arrangements" that are taxable in their own right.

The practical upshot: if you're actively trading forex, crypto, metals or shares with any regularity, your profits are taxable. The only real questions are how much, and how to calculate it properly.

What counts as trading income

Taxable:

• Realised P&L from closed trades — forex, crypto, CFDs, metals, share trading
• Profits from shares you bought to resell (most active share traders)
• Crypto gains, whether from trading, swapping, or cashing out to NZD
• Income from running a signal service or paid community

Generally not trading income (other rules may still apply):

• Long-term share gains where you never intended to resell
• PIE returns, which are taxed under their own regime
• Interest, which goes on your IR3 separately

If you're genuinely unsure which side of the line you sit on, that's the business-vs-investor question — we dig into it in the business vs passive trader guide.

The tax year and the deadline

NZ's tax year runs 1 April to 31 March. For 2025–26 you're capturing every trade closed between 1 April 2025 and 31 March 2026.

• Year end: 31 March 2026
• IR3 due: 7 July 2026
• With a tax agent: usually extended to 31 March 2027

That 7 July date sneaks up on people. Late filing penalties start at $50 and climb, so if you're not going to make it, get a tax agent on board before the deadline, not after.

Working out your taxable trading income

The formula's simple. It's the execution that trips people up.

Taxable trading income =
  Gross trading P&L (NZD)
  − Deductible expenses
  − Prior year loss carry-forward

Get everything into NZD first. Trade USD pairs on MT4 and your P&L is in USD — you have to convert each closed trade at the RBNZ mid-rate for the day it closed. Not your broker's rate, not XE, not a monthly average. The Reserve Bank's official rate, for that exact date. Done by hand, that's a separate lookup for every trade, which for an active trader runs into the hundreds. (This is the single thing TradeLog NZ automates that saves the most time.)

Then take off your costs — brokerage and platform fees, charting subscriptions, data feeds, a VPS if you run an EA, trading-specific education, accountant fees, and the trading-use share of a home office. Full detail in the deductions guide.

Then apply prior-year losses. A net loss from an earlier year reduces this year's profit, with no expiry — a loss from 2019–20 can still offset 2025–26. See the loss carry-forward guide.

Finally, add it to your other income and run the marginal rates:

| Income | Rate |

|---|---|

| $0 – $15,600 | 10.5% |

| $15,601 – $53,500 | 17.5% |

| $53,501 – $78,100 | 30% |

| $78,101 – $180,000 | 33% |

| $180,001+ | 39% |

Marginal means each band only taxes the income inside it — the 33% rate hits the slice from $78,101 to $180,000, not your whole income.

Worked example. Salary $62,000, net trading profit $24,000, total $86,000:

• $15,600 × 10.5% = $1,638
• $37,900 × 17.5% = $6,632.50
• $24,600 × 30% = $7,380
• $7,900 × 33% = $2,607
• Income tax: $18,257.50

Filing it on your IR3

Trading income goes on the IR3. If trading is your main game it sits under self-employment income; if you've got a salary and trade on the side, it goes under other income. Either way you report the net figure — gains minus losses minus deductible costs. You don't attach your trade log or broker statements, but you do have to keep them for seven years in case IRD asks.

If your records are messy or spread across brokers, paying an accountant is money well spent — and they can get you the extension to March 2027, which takes the deadline pressure off. TradeLog NZ's Pro plan spits out a tax summary PDF with the exact figures an accountant needs, or you can share it through a read-only accountant link without handing over your login.

Provisional tax

If your residual income tax for 2024–25 came in over $5,000, you have to pay 2025–26 tax in advance, in three instalments:

| Instalment | Due |

|---|---|

| First | 28 August 2025 |

| Second | 15 January 2026 |

| Third | 7 May 2026 |

Standard method is (last year's RIT × 1.05) ÷ 3 per instalment. Miss one and IRD charges use-of-money interest — not a disaster, but completely avoidable with a bit of planning. The provisional tax guide has the full breakdown.

ACC levy — the one people forget

If IRD treats you as a business trader (most active traders are), you also owe the ACC earner levy on your self-employment income. For 2025–26 that's 1.67% on the first $152,790 of liable income — so $835 on $50,000 of trading income, $1,670 on $100,000. It lands separately from your income tax and catches people out every year. TradeLog NZ folds it into the estimate so it's not a surprise.

CARF: what it does and doesn't change

If you trade crypto, you've heard about CARF. Here's the accurate version: from 1 April 2026, NZ crypto platforms have to start collecting your transaction data, and they'll report it to IRD for the first time in mid-2027. It doesn't apply to forex or CFD brokers, and it doesn't change any tax rules — crypto trading has always been taxable as income.

What it does mean is that from 2027, IRD will have a detailed record to match against your returns. So if you've been vague about crypto in the past, the smart move is to tidy it up now. IRD treats voluntary disclosures far more leniently than things it uncovers itself. (More in the CARF guide.)

Records to keep

Seven years, specifically:

• Broker statements for every closed trade
• The RBNZ rates you used for NZD conversion
• Receipts for every expense claimed
• Your loss carry-forward workings
• Bank statements for trading-related payments

If you use TradeLog NZ, your trades, rates and calculations live in the platform and export whenever you need them.

The mistakes that come up again and again

• Wrong exchange rate. Broker rate, XE, or a monthly average won't cut it — it has to be the RBNZ mid-rate per close date.
• Forgetting prior-year losses. If you never recorded a bad year, you're overpaying in every good year that follows.
• Missing the provisional threshold. If last year's bill topped $5,000, instalments started in August — UOMI may already be ticking.
• Using US software. Koinly, CoinTracker and friends calculate capital gains. We don't have that for traders, so the answer comes out wrong.
• Filing as "other income" when it's really self-employment. It matters for your ACC levy.

Getting started

If 7 July is close and your records are a shambles:

1. Export your full trade history from every broker (April 2025 – March 2026)
2. Import it into TradeLog NZ — RBNZ rates applied automatically
3. Add your deductible expenses for the year
4. Review the tax summary on the Pro dashboard
5. Export the PDF for your accountant, or use the figures to fill in your IR3 yourself

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This is general information, not tax advice. Everyone's situation differs. Run your position past a qualified NZ accountant before filing. TradeLog NZ takes no responsibility for errors in your return.

IRD on trading income | IR3 return | RBNZ rates