Overview
The District of Columbia uses two area codes: 202 and 771. The original 202 area code, introduced in 1947, has become a symbol of DC pride and identity. As the city grew and phone number demands increased, the North American Numbering Plan Administrator (NANPA) introduced the 771 area code in 2021 to ensure continued availability of phone numbers for District residents and businesses.
Both area codes serve the entire geographic area of Washington, DC through what's known as an overlay system. This means that while existing 202 numbers remained unchanged, new phone numbers may be assigned either area code.
Dialing Requirements
All local calls within the District of Columbia require 10-digit dialing (area code + seven-digit phone number). This applies to both landline and mobile phones, regardless of whether you're calling a 202 or 771 number.
Technical Considerations
To ensure proper functionality, all telecommunications equipment and services should be programmed for 10-digit dialing. This includes:
- Life-safety systems and medical alert devices
- Security systems and alarm systems
- Fax machines and Internet dial-up numbers
- Automated calling systems and speed dialers
- Mobile phone contacts
- Call forwarding settings and voicemail services
Please remember to also include the appropriate area code on business materials and stationery, advertising and marketing materials, personal identification, emergency contact information, personal checks, and pet ID tags.