Try each of the following steps in order until the issue is resolved:
  1. If the phone number and type are blank, remove the Phone Address Import ID.
  2. If the phone number is populated, ensure you have a column for Phone Type. Verify the phone type values match the Phone Type table in the database (or mark Create new table entries on the General tab of the import).
  3. If the phone number and type are populated and an address is being imported, ensure you have the Address Import ID (link between phone number and address)
  4. In the field mapping, make sure that the Phone fields (Phone Address Import ID; Phone Import ID; Phone Type and Phone Number) are correctly mapped and have the appropriate extensions
To check the mapping:
  1. Select the Fields tab
  2. In the right frame, select the Phone field
  3. In the left frame, select the Constituent Phone section.  
  4. Double-click the corresponding field (this will place the field on the right.)
  5. Repeat for each remaining phone field that did not map in your import file.