How to merge duplicate contacts in Outlook?

Author: Kelly Last Modified: 2025-04-10

When copying or moving contacts between folders in Outlook, duplicate contacts often appear. Simply deleting them may not be the best solution, as different duplicates might contain unique information in certain fields. Instead, merging duplicate contacts ensures that no valuable data is lost. In this guide, we’ll explore two methods to merge duplicate contacts in Outlook.

Method 1: Merge Duplicate Contacts While Moving in Outlook (Manual & Limited)

Method 2: Easily Merge Existing Duplicate Contacts with Kutools for Outlook 👍 (Fast & Automated)

Method 1: Merge Duplicate Contacts While Moving in Outlook

If you’re moving contacts from Folder A to Folder B, you can enable Outlook’s built-in duplicate-checking feature to merge duplicates during the transfer. Follow these steps:

Step 1: Enable Outlook’s Duplicate Contact Detection

1. Click "File" > "Options" to open the "Outlook Options" dialog.

2. In the left pane, select "People".

3. Under the "Names and Filling" section, check "Check for duplicates when saving new contacts".

4. Click OK to save the settings.

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Step 2: Move Contacts While Merging Duplicates

1. Switch to the People (or Contacts) View, open Folder A, and select one contact. Then press "Ctrl" + "A" to select all contacts in the folder.

2. Right-click the selected contacts and choose "Move" > "B" folder from the context menu.

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⚡ Tip: If the destination folder is not listed in the menu, select "Move" > "Other Folder", choose the target folder in the "Move Items" dialog, and click OK.
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3. If duplicate contacts exist, Outlook will prompt the "Duplicate Contact Detected" dialog. Click "Update All" to merge duplicates instead of creating separate entries.

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Result

All contacts from Folder A are moved to Folder B, with duplicate contacts merged automatically based on existing contact details.

Limitations of the Method:

❌ Only Effective During Move: This method merges duplicates only when moving contacts between folders; it cannot handle duplicates already existing in a single folder.
❌ Cannot Merge Existing Duplicates: If duplicates already exist within the same folder, this method cannot merge them retrospectively.
❌ Manual Confirmation Required: Each time duplicates are found during a move, you must manually confirm the merging action in the Duplicate Contact Detected dialog box.

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Method 2: Easily Merge Existing Duplicate Contacts with Kutools for Outlook 👍

If your contacts folder already contains duplicates, Outlook doesn’t offer a built-in feature to merge them. The "Duplicate Contacts" utility in "Kutools for Outlook" allows you to quickly find, compare, and merge duplicate contacts across multiple folders.

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Step 1: Enable the Duplicate Contacts Utility

Click "Kutools Plus" > "Duplicate Contacts" to launch the tool.

shot of the Duplicate Contacts button

Step 2: Select Contact Data Files

1. In the "Duplicate Contacts – Step 1 (of 5)" wizard, select the data files where your contacts are stored.

2. Click "Next step: Specify contact folder".

shot of the Duplicate Contacts – Step 1 (of 5) wizard

Step 3: Choose Contact Folders to Scan for Duplicates

1. All Contacts folders will be listed in the "Duplicate Contacts – Step 2 (of 5)" window. Select the folders containing duplicate contacts.

2. Click "Next: Select contact fields for duplicate comparison".

shot of the Duplicate Contacts – Step 2 (of 5) wizard

Step 4: Define Duplicate Identification Criteria

1. In "Duplicate Contacts – Step 3 (of 5)", select the contact fields that should match to be considered duplicates (e.g., Name, Email, Phone).

2. Click "Next: Select the fields to be listed in results".

shot of the Duplicate Contacts – Step 3 (of 5) wizard

⚡ Tip: Checking "Search all duplicates in selected Contacts folders" will compare contacts across all selected folders. If unchecked, duplicates are searched within each folder separately.

Step 5: Select Fields to Display in Results

1. In "Duplicate Contacts – Step 4 (of 5)", choose which fields will be displayed in the results.

2. Click "Start filtering".

shot of the Duplicate Contacts – Step 4 (of 5) wizard

Step 6: Merge Duplicate Contacts

1. In "Duplicate Contacts – Step 5 (of 5)", all duplicate contacts will appear in the results pane. From the How to deal with duplicate contacts drop-down, select "Merge".

2. Click "Apply now".

shot of the Duplicate Contacts – Step 5 (of 5) wizard

Result

All duplicate contacts in the selected folders are merged automatically. Merged contacts are marked with a strikethrough in the results, indicating successful processing.

shot of the merged contacts marked with a strikethrough in the results

Advantages of the Kutools for Outlook Method:

✅ Works on Existing Contacts: No need to move contacts; this method finds and merges existing duplicates.
✅ Fast & Automated: Automatically scans and merges duplicates without requiring manual intervention.
✅ Cross-Folder Support: Merges duplicates across multiple contact folders at once.
✅ Customizable Merge Criteria: Users can define which fields should be considered duplicates, giving greater control over merging.

Note: To apply the "Duplicate Contacts" utility of "Kutools for Outlook", firstly, you should download and install Kutools for Outlook.

Which Method Should You Use?

Here’s a quick comparison of the two methods to help you decide the best solution for merging duplicate contacts in Outlook:

Method	Best For	Ease of Use	Automation	Flexibility
Merge During Move (Manual)	Users merging duplicates during transfer between folders	⭐⭐⭐	⭐	⭐⭐
Kutools for Outlook (Automated)	Effortlessly merging existing duplicates across multiple folders	⭐⭐⭐⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐⭐⭐