The phrase "address someone have on file" means the contact information that someone already has recorded or stored for a specific person, like their home or email address.
Sentences with «address someone have on file»
An email is on its way to the email address we have on file for your account. (altegris.com)
Ensure any email addresses you have on file with your accounts are current. (howtogeek.com)
Once you provide the requested information, your User Name will be emailed to the email address we have on file. (bnd.nd.gov)