The FTC says there are nine area codes that phone users should be on the lookout for: 268, 284, 473, 664, 649, 767, 809, 829 and 876. These are not domestic area codes, and are frequently used for scam calls, data harvesting, malware, and robo dialing. Returning calls to these area codes can also result in $20 or more in international charges to your bill.