International awareness and demands for sustainable development have pushed the sustainability narrative into the forefront of the United Nations' Sustainable Development Goals (SDGs). As a result, the call for sustainable business practices has never been greater. While businesses are both needed and eager to contribute to sustainable development, current literature lacks insights into how businesses can practice sustainability. This paper aims to fill this gap and develop an understanding of the different categories of sustainability practices that firms adopt, and the potentials and challenges associated with them. Based on a qualitative multiple case study, we identify four categories of sustainability practices including inspiring and informing, productizing, co-creating and system building. We integrate these findings into a sustainability maturity typology, proposing that these four practices are associated with an increasing intensity of sustainability intention, so that firms realize increasing levels of sustainability in the focal business practices as they move from inspiring and informing through to system building. The article concludes by arguing that there is no generic "one size fits all" approach to support sustainability practices as approaches need to fit a firm's sustainability maturity.