To support crossplay and cross-progression, Call of Duty®: Modern Warfare® 4 requires all players to log in to an Activision account when playing online. Activision accounts allow you to play online with friends and other players on all platforms. Since Call of Duty: Modern Warfare 4 game progression is stored on your Activision account, you also have the freedom to continue your online progression if you choose to play on a different platform you have linked to your account.
Before you can play for the first time, you will be prompted to sign up for or log in to an Activision account.
If you created an Activision account to participate in the Call of Duty: Modern Warfare 4 Beta, you can use that account again. If you choose to use a different account, you will not have access to any bonus content earned while participating in the Call of Duty: Modern Warfare 4 Beta on that account.
Please note: Your progress will not carry over if you choose to link your PlayStation, XBOX, Battle.net, Steam, or Nintendo account to another Activision account.