If a person with the billing manager role no longer needs to view or change your organization's billing information, you can remove their access to the organization.
In the top right corner of GitHub, click your profile photo, then click Your profile.
On the left side of your profile page, under "Organizations", click the icon for your organization.
Under your organization name, click Settings.
In your organization's Settings sidebar, click Billing.
In the Billing managers list, next to the name of the person you want to remove, click .