Everyone with a Microsoft account needs to have up-to-date security info, which is an alternate email address or phone number where you can get security codes.
Go to Security settings and sign in with your Microsoft account.
Under Security info helps keep your account secure choose Add security info.
Follow the instructions to enter your email or phone number, then press Next.
You’ll get a security code at the email or phone number you just added. Enter that security code, and press Next again. Your new security info will appear in your list.
Article ID: 4026473 - Last Review: 20 Nov 2017 - Revision: 4