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Sorry to reply to an extremely old comment but I found an app which is free and can fix seven and 10 digit numbers. Just set the number of digits for international numbers to 10 and then put the prefix as 1. Then set the number of digits for national numbers as 7 and the prefix as 1 then your area code. You should add it to your website
https://play.google.com/store/apps/details?id=com.sergiocarvalho.android.phoneprefixer