When you are a NZ tax resident you are required to declare your worldwide income in your NZ tax return which includes your overseas investment property.
The way it works is that the costs are deducted off the rental income – if the costs are higher than the income a loss occurs – this loss can be offset against your NZ earnings which can result in tax refunds. If a profit is achieved you will be required to pay tax on the profit.
The information that you are required to keep and to provide for this accounting work to be prepared are…
Costs paid like rates, insurance, mortgage interest, power and other associated property costs.
The income and costs will also need to be convert to NZD so you can provide the information in the property’s countries currency and these can be converted based on the exchange rates at that time.