Area Code 667 – Maryland
The phone area code for Maryland is 667 (international format +1667). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 667
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Maryland
Overview of Area Code 667
Area code 667 is a geographic telephone area code in the North American Numbering Plan (NANP), serving the state of Maryland in the United States. It is an overlay code for the western portion of the state, specifically covering the Baltimore metropolitan area and surrounding regions. The code was introduced in 2017 as an overlay for the existing area codes 410 and 443, which had reached exhaustion due to the growing demand for telecommunication services.
Geographic Coverage and Jurisdiction
Area code 667 serves the same geographic area as 410 and 443, which includes Baltimore City, Annapolis, and the counties of Anne Arundel, Baltimore, Carroll, Harford, Howard, and Queen Anne's. This region is part of the state's central and eastern shore areas, with Baltimore as the principal city. The overlay covers a mix of urban, suburban, and rural communities, reflecting the diverse telecommunications needs of the area.
Dialing Procedures
Because 667 is an overlay, all local calls within the region require 10-digit dialing (area code + 7-digit local number). This applies even for calls between numbers with the same area code. For example, a local call from a 667 number to another 667 number must be dialed as +1 667 123 4567. International callers must dial +1 667 followed by the 7-digit subscriber number. For calls from within the United States, the standard international prefix (011) is not needed; instead, dial 1 + area code + number.
Numbering and Assignment
Area code 667 is assigned to wireline, wireless, and VoIP services alike. It is not specific to any particular carrier or technology. The overlay ensures that new numbers can be assigned without the need to split the region, preserving the existing 410 and 443 numbers. This approach minimizes disruption for businesses and residents.
Caller Instructions
For local callers within the overlay area, always include the area code when dialing. For callers from outside the region but within the United States, dial 1 + 667 + the 7-digit number. International callers should dial their country's exit code, then 1, then 667, then the number. For example, from the UK, dial 00 1 667 123 4567. It is important to note that 667 is not a toll-free code; standard rates apply based on the caller's plan.