Systems and methods are provided for interconnecting proxy directories, through core proxy services. One example computer-implemented method includes receiving, by a first proxy service core computing device, from a participant, a proxy lookup request, where the proxy lookup request includes a proxy and based on one or more routing rules, submitting the proxy lookup request to a second proxy service core computing device. The method also includes receiving, by the first proxy service core computing device, from the second proxy service core computing device, a proxy lookup response, which includes account data linked to the proxy, and returning the proxy lookup response, to the participant, in response to the proxy lookup request.