An entity would cease to be a 'startup' upon expiry of:
Startup is an emerging company with high growth potential, it is designed to grow rapidly with scalable business model and built to solve a problem.
In Other Words: Startups are young companies that are formed to create a one-of-a-kind product or service, bring it to market, and make it compelling and irreplaceable to clients.
Small businesses grow within a limit and this happens only within a certain circle of customers. Whereas startup does not put any limit on its growth. And it focuses on increasing its market share as much as possible.
There are six varieties of startups: