Forum Discussion
Outlook contact CSV import corrupts existing contacts without warning
Outlook (classic) corrupts existing contacts during CSV import without any warning.
When I re-import a CSV exported by Outlook itself (UTF-8 with BOM),
the contacts lose their names and email addresses and appear as
“Name not available”.
Using the exact same CSV content re-encoded as Shift-JIS imports correctly.
This behavior is reproducible and cannot be prevented by user actions.
It appears to be a defect or a flawed design in Outlook’s CSV import logic.
Please investigate and provide an official explanation.
2 Replies
That sounds like a serious issue, especially since contact data is difficult to restore once overwritten. Before importing a CSV, I always create a backup of the existing Contacts folder or export it to a PST/CSV as a safeguard. It would also be helpful if Outlook displayed a preview of the changes and a clear warning before modifying existing contacts. Hopefully Microsoft investigates this, because silent data corruption during import can have a significant impact on users managing large contact lists.
Hi HatredNamiki, before trying another import, export and back up the current contacts so you have a rollback point. CSV imports are very sensitive to column mapping, encoding, and duplicate handling, even when the CSV originally came from Outlook. I would test with two or three contacts in a separate contacts folder first, manually verify the field mapping, and avoid importing over existing contacts until the mapping is proven. If Outlook is corrupting its own export/import format, that is worth reporting with a sample CSV that has private data removed.
