Net-zero pledges have become a paradigm of ambitious climate change action for companies, governments, and other organisations. However, there is no international standard or criteria to assess whether those commitments are feasible or truly represent a landmark in low carbon performance. In this paper, a methodology is proposed against which those statements can be quantified and assessed. The methodology was applied to Spanish companies that report to the Carbon Disclosure Project and showed that the biggest areas for improvement are the design of action plans, calculation, and offsetting. From a sectoral perspective, the energy sector, finance, and other services stood out as those with the highest scores. The food, beverages and tobacco, industry, and the entertainment industry obtained the lowest results. From a technical standpoint, strategy and commitment, calculation and scope, and communication are the areas where companies had the highest average scores. On the contrary, offsetting and action plans are the areas with the greatest room for improvement. Still, actual commitments are not enough to meet international climate neutrality objectives in the long-term and companies should continue to work in this direction. An enabling regulatory framework would be very useful to align private and public action in this area.