Learn How to Merge Duplicate Contacts in Outlook 365?


Microsoft Outlook is well used for various purposes in companies and at home as an email client for communication and managing tasks. It allows users to create multiple accounts, contact folders, and calendars at a time. Due to several contact folders in Outlook, users want to merge duplicate contacts in Outlook for easier use. To justify this task for users, we have the complete solution to Merge Outlook contacts from different accounts.

These duplicate contacts take up free space and can cause inaccuracy if they are incorrect versions of the right contacts. So it’s better to find duplicate contacts in Outlook and merge them with the help of the Sysinfo PST Merge Tool.

Why does Outlook Keep Creating Duplicate Contacts?

  • It occurs while importing contacts from various devices.
  • When multiple contacts are created for the same user from different email addresses.
  • During the synchronization of contacts from social media.
  • While importing contacts from numerous email clients.

How to Merge Duplicate Contacts in Outlook?

Merging duplicate contacts in Outlook is an excellent task; it helps users manage their contacts efficiently. We provide you with two different methods to find duplicate contacts in Outlook and merge them.

Merge Outlook Contacts using the import-export features of Outlook

Step 1: Make a New Contacts Folder

  • Open Outlook and create a new folder for contacts.

Step 2: Move Outlook Contacts to the new folder.

  • Move all the contacts saved in your Outlook address book to your newly created folder.

Step 3: Export Contacts to CSV files

  • Click on the File menu and then the open/export option.
  • Tap on Export a file, then Next.
  • Choose “CSV” and click on Next.
  • Now, Select the newly created folder and click Next.
  • Click on the Browse button and set the destination path.
  • Now, Click on Finish.

Step 4: Import Contacts From CSV File to Default Contacts Folder

  • Go to File and click Open/Export>> Import/Export.
  • Now, choose Import from another program or file and press Next.
  • Choose CSV and press Next.
  • Browse the exported CSV file and select the do not import duplicate items box.
  • Select your main Contacts folder, which is currently empty, to import the contacts.
  • Now, Click on Finish

Step 5. Merge the New Contact folder with the Primary  folder

  • Open the New Contact folder.
  • Select all contacts from the folder and move them into a primary folder.
  • Next, click on the Update button to merge duplicate contacts in Outlook.
  • Once all the Contacts get merged, delete the newly created folder.

As per the above procedural steps to merge duplicate contacts in Outlook 365, you can face some problems while removing duplicate contacts. This process is too time-consuming and requires technical skills. But we also have an easy way to Merge duplicate contacts to Outlook with the help of automated software.

How Do I Merge Duplicate Contacts in Outlook Professionally?

If the above given manual methods don’t work, you must try this professional method that experts recommend. In this method, you can merge duplicate contacts in Outlook with the help of the PST Merge Tool.

Sysinfo PST Merger tool is an efficient tool to merge multiple duplicate contacts into one and reduce the file size. This software offers a cost-balancing and reliable option to merge Outlook items into one like Calendar, Emails, Journals, etc.

Key Features of PST Merger

  • Can Merge Multiple PST Files at a time.
  • Allows to remove of duplicate mailbox items
  • It can create new PST files for every folder.
  • Exclude deleted items during the merging process.
  • It combines 25 items of each PST file.


In this technical blog, you’ll find the complete solutions to Merge duplicate contacts in Outlook 365 with the help of two different methods: i.e., Manual and Professional. Here, you can also learn why Outlook keeps creating duplicate contacts and its effective solutions.