The decision to upgrade Enterprise Systems (ES) is influenced by various factors, which are either in-ternal or external to the organisation. Although previous studies have explored these factors, the ma-jority of these studies have focused on Enterprise Resources Planning (ERP) systems only. Thus, this study through a qualitative survey design draws from the expertise of 41 respondents representing 23 large organisations the different factors that influence upgrade decisions of the entire ES landscape. The paper utilises the Technology-Organisation-Environment (T-O-E) framework as a theoretical lens to classify the upgrade drivers into three main contexts: technological, organisational, and environmen-tal. The paper’s findings suggest that upgrade decisions are dependent on establishing the need to up-grade, which relies on the interaction of the numerous technological, organisational and environmental drivers. This classification facilitates organisations to easily comprehend the different drivers influenc-ing the decision to upgrade their systems.