Local governments have integral roles in contributing to public health. One recent focus has been on how local governments can impact community nutrition by engaging food service outlets to improve their food offer. The Healthier Catering Commitment (HCC) is an initiative where London local governments support takeaways and restaurants to meet centrally defined nutrition criteria on their food options. Using the case of HCC, the current study aims to provide (1) practical learnings of how local governments could facilitate and overcome barriers associated with implementing healthy food service initiatives in general, and (2) specific recommendations for enhancements for HCC. Key informant, semi-structured interviews were conducted with local government staff involved in HCC, exploring barriers and facilitators to HCC implementation in food businesses. A thematic analysis approach was used, with results presented according to a logic pathway of ideal implementation in order to provide practical, focused insights. Local governments implementing HCC. Twenty-two individuals supporting HCC implementation. Facilitators to implementation included flexible approaches, shared resourcing and strategically engaging businesses with practical demonstrations. Barriers were limited resources, businesses fearing negative customer responses and low uptake in disadvantaged areas. Key suggestions to enhance implementation and impact included offering additional incentives, increasing HCC awareness and encouraging recruited businesses to make healthy changes beyond initiative requirements. In order to facilitate the implementation of healthy food initiatives in food outlets, local governments would benefit from involving their environmental health team, employing community-tailored approaches and focusing on supporting businesses in disadvantaged areas.