You have 20 working days after the date you first contacted Work and Income (“date of first contact”) to complete your application.
If you don’t complete it in time, your application will lapse and you’ll have to start the whole process again. This might also delay when your benefit will start.
You can ask for an extension if you have a “good and sufficient” reason – for example, if:
you weren’t able to get a doctor’s appointment in time due to high demand
you had an unexpected family event, or
Work and Income didn’t let you know what evidence they need for your application.