The IPO allotment mechanism depends on the investor category and IPO subscription levels. If an IPO is undersubscribed in each investor category, all investors with valid applications will receive full allotment. An IPO must receive at least 90% aggregate subscription to be successful. If an IPO is oversubscribed for one category and under-subscribed for another category, the oversubscription can be adjusted with the under-subscribed portion of the other category except QIBs. In case of oversubscription, the issuer will allot shares based on a lottery system or proportionately based on the investor category. Let’s take a look at the IPO allotment criteria for each investor category. When a company launches its new IPO, the general public applies for it and after this the company allots shares to the applicants in the allotment process. This process is conducted by some major registrars, such as: