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To gain citizenship through this method, you need to have one parent who is or was a New Zealand citizen. In other words, if one of your parents moved out of New Zealand and you were born elsewhere, you are eligible for this type of citizenship. If you were born in New Zealand but have lived elsewhere, you may already be a citizen by birth. The citizenship office can tell you more, so contact them to find out about the status of your citizenship. You can also gain citizenship this way if you were adopted from another country by parents who were New Zealand citizens. However, you will need to provide more documentation with your application, including your adoption documents.
Have one parent who is a New Zealand citizen. Check for citizenship if you were born in the country. Gain citizenship by adoption.