Tax: New Zealand keeps its claim until you leave for good
You stop being a New Zealand tax resident only if you have no permanent place of abode in New Zealand (somewhere you can call home, even if you rent it out while away) and are away more than 325 days in any 12-month period. Until then, New Zealand taxes your worldwide income, including overseas salary and interest from overseas bank accounts, whether or not you bring the money home; you file an IR3 with the overseas income summary (IR1261), normally by 7 July, and you might be able to claim a credit for foreign tax paid.
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With no tax agreement between the two countries, there is no agreement tie-breaker if both claim you as a resident, and the Cambodian residence test (more than 182 days in a calendar year) is separate from New Zealand's 183-day test. If your residency does change, tell your New Zealand bank or investment provider so the right non-resident withholding tax is deducted.
Sources: Inland Revenue (New Zealand). Checked 16 October 2026.