ChamTax is a free calculator that shows the actual after-tax take-home amount for US Powerball and Mega Millions jackpots. Here's how a US lottery win is taxed for a New Zealand resident — a flat 30% US withholding that's generally final, and $0 additional tax from the IRD.
Last updated: 2026-08-20
$1,000,000 win, New Zealand resident estimate
At a reference USD→NZD rate of roughly 1.66, that $700,000 take-home is about NZ$1,162,000 — the calculator above converts your own amount using a live exchange rate.
No. Inland Revenue (IRD) doesn't treat gambling or lottery winnings as taxable income at all — it's classified as a "windfall gain," the same category as a gift, because the outcome is determined by chance rather than being the product of systematic effort. This isn't a foreign tax credit offsetting some computed New Zealand tax bill down to zero (the way it works for a few other countries this calculator covers); there's simply no New Zealand tax base for gambling or lottery winnings in the first place, whether the prize comes from Lotto NZ or a US Powerball or Mega Millions jackpot. So a New Zealand resident who wins a US lottery jackpot owes $0 additional NZ tax on top of whatever the US withholds.
The one narrow exception: if someone's gambling activity itself rises to the level of a systematic business or profession — a professional gambler — winnings can become taxable income. That doesn't apply to an ordinary player who buys a ticket and wins.
The US taxes nonresident aliens on lottery winnings at a flat 30% federal withholding rate (IRC §871(a)) — higher than the 24%-withheld/37%-top-rate treatment that applies to US residents, and withheld immediately when the prize is paid out.
This calculator has not researched a specific treaty-refund pathway for New Zealand residents, so a New Zealand resident's US lottery win should be assumed to be withheld at the same standard 30% nonresident-alien rate as winners from most other countries this calculator covers. For a lottery win specifically, that 30% withholding is generally the final bill, not a deposit you can reclaim.
The prize itself is tax-free, but what it earns afterwards is taxed under the normal rules — this is a general IRD principle that applies to any windfall, not something specific to lottery winnings, but it's worth knowing before you decide what to do with a large payout.
None of this changes the tax treatment of the prize itself — it's about ordinary income tax rules applying to whatever you do with the money next. A qualified New Zealand tax adviser can help with investment structuring for a large windfall.
Moving a large lump sum from the US into a New Zealand bank account doesn't create any extra tax by itself — but it will very likely be reported. Under New Zealand's Anti-Money Laundering and Countering Financing of Terrorism Act, banks and other reporting entities must file an International Funds Transfer (IFT) report with the NZ Police Financial Intelligence Unit (FIU) for any transfer into or out of New Zealand of NZ$1,000 or more. A six- or seven-figure inbound wire from a US lottery payout will be reported as a matter of course — this is a routine anti-money-laundering data feed, not an audit trigger or a tax event, but your bank may also ask you to explain the source of funds as part of its own customer due-diligence checks before releasing a very large transfer.
Keep your prize confirmation or payout documentation on hand — it's the easiest way to answer a bank's source-of-funds question quickly.
See your own after-tax amount as a New Zealand resident
Open the calculator →The US withholds a flat 30% federal tax from a nonresident alien's lottery winnings (IRC §871(a)) before you ever see the money. On the New Zealand side, the IRD doesn't treat gambling or lottery winnings as taxable income at all — it's classified as a windfall gain, because the outcome is determined by chance rather than the product of systematic effort — so a New Zealand resident owes $0 additional NZ tax on top of that. The 30% US withholding is the whole story for most New Zealand winners.
Yes. The IRD's windfall-gain treatment of gambling and lottery winnings applies equally to domestic prizes — Lotto NZ's Powerball, Strike, and Lotto draws — and to a foreign win like a US Powerball or Mega Millions jackpot. The prize itself simply isn't taxable income under New Zealand tax law, regardless of where the ticket was bought. The one narrow exception is if someone's gambling rises to the level of a systematic business or profession (a professional gambler) — not the case for an ordinary lottery player.
The prize itself is tax-free, but money it earns afterwards is taxed under the normal rules — this is a general IRD principle, not specific to lottery winnings. Interest from a savings account or term deposit is subject to Resident Withholding Tax (RWT), deducted by your bank at your notified RWT rate (based on your marginal tax rate) and treated as income at tax time. Dividends from shares and other investment income follow their own normal tax rules the same way they would for any New Zealand resident.
Generally, no. This calculator has not researched a specific treaty-refund pathway for New Zealand residents, so the safe assumption is the same baseline that applies to most other countries it covers: nonresident aliens are withheld at the standard flat 30% on US lottery winnings, and for a lottery win specifically that 30% withholding is generally the final bill, not a deposit you can reclaim.
Very likely, yes — but as a routine report, not a tax problem. Under New Zealand's anti-money-laundering law, banks must file an International Funds Transfer report with the Police Financial Intelligence Unit for any transfer of NZ$1,000 or more into or out of New Zealand, so a large inbound wire from a US lottery payout will be reported automatically. This doesn't create any New Zealand tax on the prize itself — but your bank may separately ask you to explain the source of funds before releasing a very large transfer, so keep your payout documentation handy.
This page is an informational simulator only and does not broker or facilitate lottery ticket purchases. Actual tax owed depends on individual circumstances (including how you use your winnings afterwards) and the exchange rate/tax law in effect at filing time — consult a qualified tax professional familiar with both countries.