Advances in computing technology and analytical techniques have given crime analysts increasingly powerful toolboxes with which to unlock the spatial patterns and processes of crime. However, the utility of such tools is still bounded by the “garbage in, garbage out,” maxim, whereby analytical output is only as reliable as the analytical input. Therefore, this chapter reviews some of the sources of spatial data inaccuracy that must be considered when analyzing crime. Given the prevalence of street addresses as a spatial location identifier for crime events, particular attention is given to the accuracy and optimum parameters for geographically referencing address data. Example data drawn from burglary records in the city of Wollongong, Australia, illustrate the significance of the issues and the impact that poor address management can have on the analysis of crime. The chapter emphasizes the practical, by outlining address correction options and summarizing recent research that identifies optimum settings for geocoding software tools.