Area Code 227 – Maryland
The phone area code for Maryland is 227 (international format +1227). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 227
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Maryland
Overview of Area Code 227
Area code 227 is a geographic North American Numbering Plan (NANP) code assigned to the state of Maryland, serving the western portion of the state, including the state capital, Annapolis, and surrounding areas. It is an overlay code for the existing area code 410, which was introduced in 1991 to meet the growing demand for telephone numbers in the region. The overlay means that both 410 and 227 serve the same geographic area, requiring 10-digit dialing for all local calls.
Geographic Coverage and Major Cities
The 227/410 overlay region encompasses a significant part of central and eastern Maryland, including the cities of Annapolis, Baltimore, and Salisbury, as well as numerous suburban and rural communities. This area is known for its economic vitality, with a mix of government, technology, healthcare, and maritime industries. The overlay ensures that new telephone numbers are available for residents and businesses in this densely populated corridor.
Dialing Procedures
For local calls within the 227/410 area, callers must dial the full 10-digit number (area code + 7-digit local number). This applies to both landline and mobile calls. For international callers, the format is +1 227 XXX XXXX (or +1 410 XXX XXXX). When calling from outside the United States, replace the leading '1' with the international access code (e.g., 011 from many countries). For example, to call a number in Annapolis from abroad, you would dial +1 227 555 0123.
Numbering and Regulatory Context
As part of the NANP, area code 227 is regulated by the Maryland Public Service Commission and administered by the North American Numbering Plan Administrator (NANPA). The overlay was implemented to avoid the need for customers to change their existing numbers, a process known as permissive dialing during a transition period. Today, 10-digit dialing is mandatory for all calls within the region, including calls to other overlay codes in Maryland.
Businesses and residents in the 227 area benefit from a robust telecommunications infrastructure, with access to high-speed internet and advanced mobile services. The overlay also facilitates number portability, allowing customers to retain their numbers when switching service providers. For those planning to relocate to this part of Maryland, obtaining a local number with area code 227 or 410 is straightforward through any local or national service provider.