Abstract: An apartment building alerting system and method are disclosed which use the Public Switching Telephone Network (PSTN) to alert and connect visitors to residents. The PSTN system generally has a visitor interface unit located in the apartment building and is connected over a regular telephone line to a telephone switch located at an end office which serves the local area. The visitor interface unit also includes an auto dialler which takes a resident name, an apartment number or some other means for identifying a particular resident of the apartment building and translates it into a PSTN directory number (DN) associated with the telephone physically located in the resident's apartment. To contact a particular resident a visitor uses the visitor interface to identify a particular resident and the auto dialler proceeds to dial a corresponding PSTN DN associated with the resident. Where the resident answers the call the telephone switch connects the visitor with the resident over the PSTN.