With thousands of projects being built along eight transcontinental corridors, China’s Belt and Road Initiative (BRI) is driving the global infrastructure boom. BRI is likely to have a sizeable biodiversity footprint as its corridors overlap several priority areas for conservation and 150,000 km2 of critical habitat. Biodiversity safeguards for the initiative therefore warrant scrutiny. Biodiversity safeguards are policies or standards (adopted by regulators, project proponents or financiers) that specify biodiversity impact mitigation measures. Here we examine a key source of safeguards—lending requirements of BRI’s financiers. We compare them with International Finance Corporation’s Performance Standard 6, which is often regarded as international best practice and which requires projects affecting ‘critical habitat’ to achieve a ‘net gain’ of biodiversity through impact mitigation. We find that of the 65 financiers identified (35 Chinese and 30 international), just 17 require biodiversity impact mitigation and 12 require a ‘net gain’. Among those with biodiversity safeguards, 16 are international, and despite the Chinese financiers accounting for over 90% of BRI’s financing (by quantum of investment), only 1 of the 35 we identified has biodiversity safeguards. Because most BRI finance is not subject to biodiversity safeguards, we conclude that potential impacts of BRI linear infrastructure projects may remain unmitigated, despite approximately 369,000 km2 of critical and natural habitat occurring within the 25 km buffer zone of such projects. We therefore argue for urgent adherence to best-practice safeguards for all institutions financing the BRI.