Discussions regarding climate change accountability, and accordingly, the effort-sharing of climate change mitigation, have focused predominantly on the role of nation-states as the most relevant actors. Yet, companies that are contributing greenhouse gas emissions to the atmosphere have not similarly been held accountable, nor have they been given clear mitigation guidelines that follow global climate targets. In this study, I aim to encourage business accountability by highlighting the emissions contributions of public companies and the need for reliable corporate reporting and mitigation efforts. I evaluate reported company emissions in 2015, and allocate sectoral carbon emissions budgets associated with the climate targets of remaining below a global mean temperature increase of 1.5°C, and 2°C. I then provide linear, exponential, and logistic functions as future sectoral emissions pathways that conform to these budgets. I also evaluate corporate reporting patterns in the context of company market value and location. Results show that only 7% of companies worldwide report direct emissions. These companies account for a fifth of global CO2 emissions in 2015. Pathways constrained to the 1.5°C budget especially suggest that early and stringent mitigation is critical. Companies may favour the logistic pathway which accommodates an initial lag in emissions reductions, though it forecasts rigorous mitigation requirements in the near future. Weak but significant positive correlations between company market capitalization and emissions may indicate that larger companies are more likely to report greater emissions, and that market value may have potential to be used as a proxy for estimating company emissions. Sectoral level analyses would be improved if corporate emissions disclosure was widespread and verified for reliability. Achieving global climate goals requires accountability that goes beyond the nation-state boundary and that reaches businesses. Moreover, emissions disclosure paves the way for effective business mitigation efforts.