The following NXX prefixes look to be US/Canada/Mexico NANPA numbers but are in fact international destinations if called from the US. If you run an Asterisk system and are concerned about toll-fraud, then you should block outgoing calls to these numbers, many of which are high per-minute mobile numbers that quickly rack up lots of fraudulent expenses.
| 1242NXXXXXX |
| 1246NXXXXXX |
| 1264NXXXXXX |
| 1268NXXXXXX |
| 1284NXXXXXX |
| 1340NXXXXXX |
| 1345NXXXXXX |
| 1441NXXXXXX |
| 1473NXXXXXX |
| 1649NXXXXXX |
| 1664NXXXXXX |
| 1670NXXXXXX |
| 1671NXXXXXX |
| 1684NXXXXXX |
| 1721NXXXXXX |
| 1758NXXXXXX |
| 1767NXXXXXX |
| 1784NXXXXXX |
| 1787NXXXXXX |
| 1809NXXXXXX |
| 1829NXXXXXX |
| 1849NXXXXXX |
| 1868NXXXXXX |
| 1869NXXXXXX |
| 1876NXXXXXX |
| 1939NXXXXXX |
| 242NXXXXXX |
| 246NXXXXXX |
| 264NXXXXXX |
| 268NXXXXXX |
| 284NXXXXXX |
| 340NXXXXXX |
| 345NXXXXXX |
| 441NXXXXXX |
| 473NXXXXXX |
| 649NXXXXXX |
| 664NXXXXXX |
| 670NXXXXXX |
| 671NXXXXXX |
| 684NXXXXXX |
| 721NXXXXXX |
| 758NXXXXXX |
| 767NXXXXXX |
| 784NXXXXXX |
| 787NXXXXXX |
| 809NXXXXXX |
| 829NXXXXXX |
| 849NXXXXXX |
| 868NXXXXXX |
| 869NXXXXXX |
| 876NXXXXXX |
| 939NXXXXXX |