Cross checking everything on online business is a must. Another parameter to check given phone number with address. Actually not all phones map to an address; mobile numbers are a non-geographic. But other numbers will map at least to city granularity like ip address. You number compare the number’s city, country to billing and shipping city and country. A mismatch must warn you.
OnVerify.com provide free number type and number address for all verifications. It’s easy to use and implement