The enormous need for mobile data is leading to a significant increase in energy consumption in mobile networks and thus to a surge in carbon dioxide (CO2) emissions. Mobile operators face the challenge of achieving their ambitious net-zero emissions target while maintaining acceptable levels of social, economic and environmental sustainability. Motivated by the increasing adoption of green communications in the era of 5G and beyond, this paper aims to examine the business model for green mobile network operators (MNOs) in the context of social, environmental and economic sustainability. Furthermore, research in this area has mainly focused on the technical aspects of green mobile networks, while less attention has been paid to the business side. To remain competitive and also contribute to the growth of emerging green mobile networks, operators should have the flexibility to rethink their current business model.