- I cannot play the game for free, when I add the cell phone I receive an error
- I cannot add my phone number to this account, I already added it to another account
- Error: The phone number for this account is already being used by another account. Please visit the Battle.net Account Settings page to add a new phone number
You will receive this error if your phone number was already linked to a free game account before. A phone number can only be linked to one free game.
If you want to play for free, you must add a different, unused phone number in your Account Settings. If you don't have a different, valid phone number, you can buy the paid version of Call of Duty: Modern Warfare.