Rationale:BGS and VCS Odense proposed this STSM based on ongoing work in both cities to improve the delivery and impact of subsurface data within the cities.Shared difficulties in improving the delivery and impact of subsurface data were highlighted between the cities at the NAG-CITY workshop discussions in Odense (January 2013). In both cities, the lack of standardised data reporting formats, and the selective legislation requirements for reporting subsurface data to national or city authorities, strongly limits the amount and accessibility of subsurface data which is available to inform decision making.Purpose:The purpose of the STSM was to facilitate knowledge exchange between specialists in VCS Odense, GEUS, Odense City Municipality and BGS to compare key issues of the subsurface data management within the cities of Glasgow and Odense, in the absence of a comprehensive legislative framework in the UK or Denmark which ensures all borehole data are submitted to national or local public authorities. The STSM also aimed to discuss methods which could be used to improve the delivery and impact of subsurface data within the cities, and which could be transferred as a best practice to other cities within the COST Action with similar legislation.Improving access to standardised subsurface data, which can be readily available to inform policy and decision making within the public and private sectors, is increasingly required in all COST cities to meet key current urban redevelopment and groundwater management demands. The lessons learnt from the STSM are, therefore, of benefit to all COST-participants, particularly those within countries of similar data legislation.