Steps to Back up Contacts to OneDrive on Windows PhoneStep 1. Find Settings List of the Email Accounts on Lumia
Go to "All apps" > "Settings" on the home screen of your Windows phone. After the settings list is shown, scroll down to find "email + accounts" under the "accounts" list.
Step 2 Sign in Outlook.com on Lumia
Choose "Add an account" > "Outlook.com" if you haven't sign in the email on your Lumia 930/640/630/535 before. Then, just enter the email address and the password to sign in.
Then, in the next window, you will see the interface below, which shows you that it can automatically save your photos to OneDrive, sync your text messages and back up phone settings and app data. You can choose "Yes" to start the backup or "Not now" to stop it.
Now the Windows Phone contacts will be automatically synced to your outlook account with ease. OneDrive is perfectly compatible with Windows phone and computer. So, you can also enter OneDrive on your computer with the same account to check for the backup record. It's not complex to back up Windows phone contacts to OneDrive, isn't it?