The sustainable business model (SBM) concept requires enterprises to integrate sustainability aspects in their planning and operations. Although 60% of the global working population make their living in the informal sector mostly in low-and middle income countries, the potential for SBMs has rarely been analyzed for this category. This study explores the SBMs of informal charcoal-producing enterprises in coastal Kenya. It describes key business-model components: value proposition, value creation and delivery, and economic value capture. Impact and dependency on sustainability-related indicators were also studied. Data were obtained through individual interviews, focus-group discussions, and workshops for charcoal producers and other relevant stakeholders. Findings demonstrated that charcoal enterprises, despite their informal status, adopt elaborate business models. The incomes positively affect several Sustainable Development Goals (SDGs) by reducing, if not eradicating, poverty and supporting basic livelihood needs. Examples of negative impacts on some SDG include the activity’s contribution to forest degradation. Feedback impacts, where SDG status influence the informal enterprises’ opportunities were also identified. The SBM model contributes to the development of a balanced sustainability transition of the charcoal sector. We suggest further analyses of the role of informal enterprises in the bioenergy sector for sustainable development and how their SBMs could be improved.