As long as you are not using a Gmail account as a verification email in Google, you can change it at any time. Log in to Google using the Google Accounts homepage (see Resources) and click the ...

Accounts are considered active if a user signs in and performs any one of a number of actions, including reading or sending an email, watching a YouTube video or using Google’s search.

To start managing your Google Business Profile in Google Search, make sure you’re signed into the Google Account email address you use to manage your Business Profile.