Prefix Information
The prefix 340 is part of area code 442 serving Oceanside, California.
This exchange contains 10,000 possible phone numbers (442-340-0000 through 442-340-9999).
Phone numbers with prefix 340 in area code 442. Location: Oceanside, California.
The prefix 340 is part of area code 442 serving Oceanside, California.
This exchange contains 10,000 possible phone numbers (442-340-0000 through 442-340-9999).