How do I validate the phone numbers of contacts I have already imported?

If your school has  Phone Number Validation enabled, you can generate a Contact Data export and sort the Validation Status column by Unvalidated to see a list of all imported contacts who have not had their phone numbers validated. You can then copy/paste those numbers into the ad-hoc validation tool.

1. To generate the Contact Data report, navigate to Team Name > Reporting > Exports, choose Contact Data from the drop-down list, and click [Request Export] to receive an email with the file. Sort the Validation Status column by Unvalidated to isolate the phone numbers you want to validate.

2. Copy the phone numbers and navigate to Teams Name > Data Management > Number Validation. Paste the phone numbers into the text box and click [Validate].