We investigate the impact of government environmental credit ratings on bond credit spreads based on a sample of Chinese A-share listed companies from 2014 to 2022. Empirical results demonstrate that a favourable environmental credit rating significantly reduces bond credit spreads, highlighting the incentivising effect of environmental credit ratings. Mechanism testing reveals that a good environmental credit rating diminishes information asymmetry and enhances an enterprise’s resource acquisition capabilities, reducing bond credit spreads. Furthermore, subgroup analyses suggest the reduction effect is more pronounced in enterprises with low debt and tax credit ratings.