Now you can easily set up and use Facebook Chat and Messenger for Windows Phone. Windows Phone has is the built-in Facebook chat support; theoretically, you can Fb chat straight from the Messaging application in your Windows Phone, the problem is that your Windows Live ID is not linked with Facebook. Simply follow the steps below to link your Live ID with Facebook to get Facebook Chat on Windows Phone working.
How to set up and use Facebook Chat and Messenger for Windows Phone
Step 1. Add your Facebook account to your Windows Phone (Settings > Email and Accounts).
Step 2. Head to live.com and login using your Live ID (the same one that’s used on your handset).
Step 3. Under “Messenger Social” (where all your contacts updates are displayed) select “Add” next to the list of connected networks.
Step 4. Connect your Facebook account to your Live ID and grant permissions.
Step 5. Ensure that ample permissions are selected, especially “Chat with Facebook friends”.
Step 6. Now go to “Messaging” in your WP and slide to the right, set your status to “available,” you should see all your fb friends there. Conversations will be managed like SMS, it’s really cool!
Step 7. If you for some reason this doesn’t work, reboot your phone and go to settings>slide to the right>Messaging> turn fb chat on
Now you’ll be able to utilise Facebook Chat on your Windows Phone with the above steps carried out.