No — you don’t need to finish all instalments before the infringement due date.
For Auckland Transport (AT) infringements, the date you pay your first Zip instalment is treated as the date the fine is paid.
Zip pays the full infringement amount to Auckland Transport upfront. You then repay Zip in instalments over time.
To avoid late penalties from AT, make sure your first instalment is successfully paid before the due date on your infringement notice.
You can find step-by-step instructions on how to pay an AT infringement with Zip in this article.