An Emergency Services Application Server (ES-AS) that obtains routing instructions for both VoIP-originated and non-VoIP-originated calls to emergency services numbers (e.g., 9-1-1). If the emergency request is a VoIP-originated call and includes a location object, the ES-AS queries its database using the location object to obtain routing information. If a location object is not provided, the ES-AS queries a location information server to obtain a location object. The ES-AS then uses the location object to query its database. If the call is originated by legacy user equipment, the ES-AS accesses a legacy automatic location information system to obtain location information and the associated PSAP. The ES-AS then queries its database with the returned information to refine routing information needed to route the call to the identified PSAP. The ES-AS includes a web services interface that allows a PSAP or authorized agency to change routing instructions dynamically, which overrides any static data in the ES-AS's routing database.