Prefix Information
The prefix 399 is part of area code 240 serving Germantown, Maryland.
This exchange contains 10,000 possible phone numbers (240-399-0000 through 240-399-9999).
Phone numbers with prefix 399 in area code 240. Location: Germantown, Maryland.
The prefix 399 is part of area code 240 serving Germantown, Maryland.
This exchange contains 10,000 possible phone numbers (240-399-0000 through 240-399-9999).