inconsistent results trying to upload Personal Contact List via CSV?

I found a solution through another tech forum.

SUMMARY: After dozens of trials with file changes, I discovered that RingCentral uses a variant of CSV, and that version is not directly compatible with Excel for Mac. RC expects that every field entry in a CSV file is delimited with double quote marks, even blank fields. The following sample line shows what this looks like in text form for six fields where only the first two fields contain data.

“John Doe”,”123 Main St”,””,””,””,””

Using Excel for Mac, the export to CSV for the same six field values produces this result:

“John Doe”,”123 Main St”,,,,

SOLUTION: There’s an Excel custom format technique to force double quote marks in cells that do contain data. After saving a CSV version of the file, use TextEdit to find/replace all the null fields with delimited fields.