One hurdle I came across was setting up Outbound Routes and Trunks for calls within the US and Canada (on unlimited plan), but due to the NANP (North American Numbering Plan) there are lots of other area codes that are outside the US and Canada that will match the dial pattern (and cost you big bucks if called).
So I did some research, and this is my list of dial patterns I came up with that need to be blocked… hopefully this is useful to somebody else. I can also send you an Excel spreadsheet with these in them if you want, just PM me.
Dial Patterns for North American Numbering Plan
Information taken from the following websites:
en.wikipedia.org/wiki/List_of_No … ring_Pla….
nanpa.com/
Special Purpose (probably will always want to block these)
456NXXXXXX 1456NXXXXXX 456 numbers
500NXXXXXX 1500NXXXXXX 500 numbers
522NXXXXXX 1522NXXXXXX 522 numbers
533NXXXXXX 1533NXXXXXX 533 numbers
544NXXXXXX 1544NXXXXXX 544 numbers
566NXXXXXX 1566NXXXXXX 566 numbers
577NXXXXXX 1577NXXXXXX 577 numbers
588NXXXXXX 1588NXXXXXX 588 numbers
600NXXXXXX 1600NXXXXXX Canada Remote Satellite Phone Service
700NXXXXXX 1700NXXXXXX 700 numbers
900NXXXXXX 1900NXXXXXX 900 numbers
NXX976XXXX 1NXX976XXXX Any area code + 976 + XXXX
Outside Canada/US (These are international calls, so may want to block them)
242NXXXXXX 1242NXXXXXX BAHAMAS
246NXXXXXX 1246NXXXXXX BARBADOS
264NXXXXXX 1264NXXXXXX ANGUILLA
268NXXXXXX 1268NXXXXXX ANTIGUA/BARBUDA
284NXXXXXX 1284NXXXXXX BRITISH VIRGIN ISLANDS
345NXXXXXX 1345NXXXXXX CAYMAN ISLANDS
441NXXXXXX 1441NXXXXXX BERMUDA
473NXXXXXX 1473NXXXXXX GRENADA
649NXXXXXX 1649NXXXXXX TURKS & CAICOS ISLANDS
664NXXXXXX 1664NXXXXXX MONTSERRAT
721NXXXXXX 1721NXXXXXX SINT MAARTEN
758NXXXXXX 1758NXXXXXX ST. LUCIA
767NXXXXXX 1767NXXXXXX DOMINICA
784NXXXXXX 1784NXXXXXX ST. VINCENT & GRENADINES
809NXXXXXX 1809NXXXXXX DOMINICAN REPUBLIC
829NXXXXXX 1829NXXXXXX DOMINICAN REPUBLIC
849NXXXXXX 1849NXXXXXX DOMINICAN REPUBLIC
868NXXXXXX 1868NXXXXXX TRINIDAD AND TOBAGO
869NXXXXXX 1869NXXXXXX ST. KITTS AND NEVIS
876NXXXXXX 1876NXXXXXX JAMAICA
Other US related (these can sometimes be costly calls even though they are part of US)
684NXXXXXX 1684NXXXXXX AMERICAN SAMOA
670NXXXXXX 1670NXXXXXX NORTHERN MARIANAS ISLANDS
671NXXXXXX 1671NXXXXXX GUAM
340NXXXXXX 1340NXXXXXX US VIRGIN ISLANDS
907NXXXXXX 1907NXXXXXX ALASKA
808NXXXXXX 1808NXXXXXX HAWAII
787NXXXXXX 1787NXXXXXX PUERTO RICO
939NXXXXXX 1939NXXXXXX PUERTO RICO
Toll Free Numbers (I usually leave these unblocked, but you may want to block them)
800NXXXXXX 1800NXXXXXX 800 numbers
822NXXXXXX 1822NXXXXXX 822 numbers
833NXXXXXX 1833NXXXXXX 833 numbers
844NXXXXXX 1844NXXXXXX 844 numbers
855NXXXXXX 1855NXXXXXX 855 numbers
866NXXXXXX 1866NXXXXXX 866 numbers
877NXXXXXX 1877NXXXXXX 877 numbers
888NXXXXXX 1888NXXXXXX 888 numbers
EDIT: note that I removed area code 205 from the list as I had it listed as Alaska but it is actually Alabama … thanks Nathan for pointing that out.