The New Zealand income tax year runs from 1 April to 31 March. If you started the business prior to 1 April 2020 you would need to file an income tax return for year ended 31 March 2020 by 7 July 2020. If not then your first income tax return wouldn’t be due until 7 July 2021 (for the year ending 31 March 2021).I am assuming you haven’t registered for goods & services tax (you wouldn’t be required to if your sales are under $60,000 per annum). Because the income from this business is sourced in New Zealand you would be required to file a return and pay tax on it in New Zealand even if you aren’t a tax resident of New Zealand (would need more information to determine whether or not you are a tax resident). Unfortunately even for simple/small businesses all this can be a bit complicated to understand. My suggestions to simplify would be 1) keep a separate bank account for your business income/expenses, 2) read up on the IRD website for information about income tax for individuals (https://www.ird.govt.nz/income-tax/income-tax-for-individuals) 3) find a small local accountant to help you file your annual income tax return(s) when they fall due and 4) put aside a % of your income for tax using your marginal tax rate (the tax rate corresponding to your income level per annum in the table here (https://www.ird.govt.nz/income-tax/income-tax-for-individuals/tax-codes-and-tax-rates-for-individuals/tax-rates-for-individuals). Hope that is somewhat helpful.