To get things started, Linchpin User Profiles (also known as Contacts) offers you an easy way, to import your users contact information.
Import additional contact details for your users
With the Contacts app, you will be enabled to enrich your user entries with more powerful details. These details will be listed on the Contact list page. Since Atlassian offers poor information about users, the Contacts app provides a feature to import these user details. 
Short facts
- Supported data format: .csv (Comma-separated values)
- Supported contact fields:
fullName, email, phone, IM (Instant Messenger), website, position, department, location - Matching field between user data and Atlassian account:
email
The email column form the CSV is used to map contact information to Atlassian users. If you want to link contact information from the CSV to an Atlassian user, the email in the CSV must match that of the Atlassian user. In addition the Atlassian user must have selected to share his email address, for this to work.
Import data – Step by step
Prepare a CSV-file wich contains the contact information you want to import. Each line must contain the information of one person. The first line declares the columns and must look exactly like this:
fullName;email;phone;IM;website;position;department;location
The values in each column must not contain any additional whitespace at the beginning or end of the value. For a better understanding, please see the example below.
Example:
fullName;email;phone;IM;website;position;department;location John Doe;jdoe@company.com;+491234567890;jdoe@jabbra.com;https://jdoe.blog.com;Product Manager;Online Department;Berlin
Head over to the Confluence administration section and locate Contacts from the sidebar. Select the User data import tab.
Click the Upload button and select the CSV file, you prepared in step one.
Now the file is uploaded and the import process for the contact information is running in the background. You do not need to keep this page open while the import is running. When you want to see the progress, there is is an indicator showing how many contacts have successfully been imported and mapped to a Atlassian user account.
Link to this page: https://seibert.biz/cloud-contacts-import-csv