actually now Geico is sending conflicting emails so not sure now maybe a insurance expert can chime in
see their response below:
We want to do everything we can to help clarify how "Joey" would be covered in a rental vehicle by your policy. We're sorry for the previous miscommunication regarding your question.
GEICO would cover "Joey" from insurance perspective, but rental companies have other rules and insurance coverage doesn't override that.
You asked what would happen if he is not authorized on the rental, but covered on your policy. To answer your question, there would be no changes to the GEICO policy, and "Joey" is already listed as an active driver.
However, please understand that we cannot review the rental contract you have, and we cannot review possible changes to your rental contract if you allow an unauthorized driver to operate the rental. To further review this, you would need to contact the rental agency directly.
Sincerely,
Martha W.
GEICO Internet Team
Government Employees Insurance Company
GEICO General Insurance Company
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GEICO County Mutual Insurance Company
In order to protect your privacy, please do not include personal information in a reply email (examples include driver's license number, social security number, date of birth, or financial account details). To provide us with this information, simply log into your policy at geico.com and make the necessary updates or, while logged in to your policy, select Contact Us to send an email. If you prefer, you can call us, anytime, at 1-800-841-3000.