ZIP code 01831 is officially located in the state of Massachusetts, primarily serving the city of Haverhill. It falls under the administrative jurisdiction of Essex County. When planning mail delivery, logistics routing, or demographic research, 01831 operates within the Eastern Time (ET) timezone and supports the 881 area codes.
According to the latest US Census Bureau and American Community Survey (ACS) datasets, the total population residing within the 01831 ZIP Code Tabulation Area is approximately Data Not Available. Understanding local economics is critical for market analysis; the median household income in this postal area sits at $67,831.