Clearing or Deleting Contacts

Question

I have exported my Contacts list, run co-pilot to de-dup and tried to delete my current contacts list to import the de-duped file. There does not seem to be a way to "mass" delete the contacts either on desktop or outlook.com, except for 50 at a time. At this point I have over 4K contacts because of the multiple attempts to clear/clean up my contacts! What is the most time efficient manner to fix this issue?

Answer 1

@Riki F. Lovejoy said

does not seem to be a way to "mass" delete the contacts either on desktop or outlook.com, except for 50 at a time

Correct. Only Classic Outlook for Windows can do a "mass" delete.
https://learn.microsoft.com/en-us/answers/questions/4687664/deleting-more-than-50-contacts-in-people

New Outlook does do some very simple dedup. But not that will clean up what it sounds like you have.
https://support.microsoft.com/en-us/office/manage-duplicate-contacts-in-outlook-0fa9c0a0-499a-48ab-b818-4e6463ccb9fa

Also, the "AI answer" seems to have assumed that you have Classic Outlook since it talks about a "Replace duplicates with items imported" option which does not exist in New Outlook for Windows or Outlook Web.

Answer 2

There is no supported bulk “delete all contacts at once” option for Outlook/Outlook.com contacts in the provided material. The most time‑efficient supported pattern in context for large contact changes is:

1. Export all contacts to a CSV file.
2. Fix or de‑duplicate them outside Outlook (for example, in Excel or another tool).
3. Import the cleaned CSV back into Outlook using the option to replace existing items.

This avoids manually deleting thousands of contacts and lets the import process overwrite the existing contacts with the cleaned set.

The relevant guidance shows this pattern for bulk contact fixes:

1. Export contacts to CSV.
2. Edit the CSV in Excel (for example, remove duplicates or move data between fields).
3. Import the modified CSV back into Outlook and choose Replace duplicates with items imported so the imported items overwrite existing ones.

This same approach is used to:

• Fix uneditable contacts in bulk by exporting, then importing with Replace duplicates with items imported.
• Reduce multiple entries per contact by exporting, editing in Excel, then importing the modified CSV back into Outlook.

Applied to the scenario:

1. Export the current full contacts set to CSV (as a backup).
2. Use the already de‑duplicated CSV file as the source.
3. Import that de‑duplicated CSV back into Outlook and, when prompted how to handle duplicates, select Replace duplicates with items imported so the cleaned contacts overwrite the existing ones instead of creating more copies.

This is the most efficient supported method in the context for bulk cleanup without deleting contacts 50 at a time.

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References:

• Unable to edit Contacts, Appointments, Meetings, or Tasks within Outlook
• Contacts in the Outlook Address Book are listed multiple times
• Fix problems importing contacts to Outlook
• Import Gmail contacts to Outlook
• Microsoft 365 operated by 21vianet: Import contacts to Outlook for Windows
• Video: Manage contacts on your desktop