\+?(\d+)?[ \.-]?\(?(\d{3})\)?[ \.-]?(\d{3})[ \.-]?(\d{4})
This regex matches most NA phone number formats without extensions, including
250-370-8517
604-851-4700
+12503708517
+1232503708517
1.250.370.8517
123.250.370.8517
+1 (250) 370-8517
+123 (260) 359-1583