iPhone contacts aren't syncing to iCloud

Contacts on my iPhone 4 are not syncing to iCloud even though it is set as on. It is a new phone, and the contacts synced when I first set up iCloud, but not since. I have tried "backup now" and new notes appeared, but no new contacts.

This is what worked for me after speaking with a very helpful Apple senior tech agent:

Open Settings> Mail, Contacts, Calendars> Contacts – Default Account = must contain a check next to iCloud.That’s it! Now all future contacts created on your iPhone (on your iPad, do the same as above), will also appear in iCloud and Outlook (if you’ve also set up Outlook).

If you have contacts that are already only on your iPhone/iPad then you’ll want to: Open Phone> Contacts> Groups (top left corner)> Hide All Contacts (top left corner). Then select/Checkmark all email accounts/accounts you see listed and make sure that iCloud it NOT check marked here while you’re fishing for all those rogue contacts. Click done and what will then be displayed, are contacts that you saved somewhere other than iCloud. Then recreate these contacts you see, one by one, by going into iCloud.com, your other iDevice or Outlook on your desktop and create them as new contacts. For best results I recommend that you DO NOT press save for the new contact until you FIRST press delete* on the non-iCloud contact you are about to make a copy of. Of course press delete only after you’ve copied all of the contact data.

• To delete a contact on your iPhone/iPad: Contacts> select the contact> tap Edit (top right corner)> Scroll to the bottom and select Delete Contact.

If you have more than one account with contacts, make sure your contacts are saved to your iCoud account and not any other (Settings -> Mail, Contacts, Calendar -> Contacts -> Default Account -> iCloud (or what ever you've named it). I use Gmail as main account, and therefore new contacts aren't added to my iCloud by default.

If you've done that and it still doesn't work, remove your iCloud account from you settings (Settings -> Mail, Contacts, Calendar -> iCloud (or what ever you've named it) -> Delete Account). Restart your phone and add it again and restart it once again. Your contacts, notes, events etc will NOT be deleted from your iCloud account, but any data NOT synced WILL (does not affect other account of course)!

Edit: 2017-01-18 ~ With the advent of all the feature rich apps on your phone, you're likely to find that other apps besides the Contacts configured ones have access to add/modify your contacts, such as Facebook. This is why sometimes you have the same person show up multiple times on your phone, and not on your computer or other devices.