Master Street Address Guide (MSAG)-validated street address data is correlated with real-world geographic (e.g., latitude/longitude) data. Conventional MSAG-validated street address data is processed, or geocoded, into an additional (or integrated) database that associates latitude/longitude information with a particular entry in the existing MSAG-validated database. The association of the lat/lon data may be direct, or indirect using link ID or other unique tags indicating a particular entry in the MSAG-validated database. The geocoding need be performed only once by a service provider, e.g., as part of the deployment of an emergency service system. In this way, the closest public service answering point (PSAP) to a given latitude/longitude position of a wireless or VoIP device may be determined quickly, providing emergency services with the smallest possible reliable response time.