Prefix Information
The prefix 503 is part of area code 410 serving Baltimore, Maryland.
This exchange contains 10,000 possible phone numbers (410-503-0000 through 410-503-9999).
Phone numbers with prefix 503 in area code 410. Location: Baltimore, Maryland.
The prefix 503 is part of area code 410 serving Baltimore, Maryland.
This exchange contains 10,000 possible phone numbers (410-503-0000 through 410-503-9999).