The legal and institutional framework pertaining to Underground Built Heritage (UBH) plays a crucial role in preserving underground heritage and shaping regeneration policies for underground spaces in both urban and rural areas. It complements formal planning policies and procedures while interacting with informal planning practices. To provide an overview of the primary regulatory instruments and key authorities and organizations related to UBH, experts participating in the COST action, specifically the Underground Built Heritage Planning Approaches Working Group, developed an Excel template. This template was designed to be completed by local experts from each country participating in U4V.