Add more than one phone number to security verification

In the security settings, please make it possible that we can add at least ONE other phone number to our security verification process on the login. If the security phone gets lost or the person is inaccessible or driving and wont answer the text request, etc then only having one security phone number could be a big problem. We should be able to choose between at least 2 if not 3 phone numbers that we pre-certify as valid security numbers to allow login...