If you want to get credit for prior study, this is called “cross-credit” or “exemption”. It means that if you have done the first year of a course in your own country and want to go straight into the second year in New Zealand, you can apply to do so. This must be negotiated with the institution you are applying to study at.
If your previous study was in an English-speaking country, the process will be easy.
If not, it may simply be a matter of providing the faculty department (Science, Hospitality, Geography, etc.) with a detailed description of the course you have studied so far.
In other cases, it may be necessary for the Qualifications Evaluation Service at NZQA to assess your incomplete qualification. They will only do this if the purpose is further study, i.e. if you intend to complete the qualification by studying in New Zealand. The fee is NZ$450 and the process takes around eight weeks. You will have to provide certified photocopies – or, for some countries, the original documents – and translations from an NZQA-approved translation agency. In certain cases, the assessment may be “prioritised” and may not take quite so long.