How to set up policy banners in macOS
Find out how to set custom banners to appear at the login window on your Mac.
A policy banner is a banner that is displayed at the login window that requires you to acknowledge it before proceeding.
Find out more about policy banners
You can set a login message You can also set a "policy" banner to display a longer message that you must accept before you can log in. This can be useful in situations where you need users to agree to or acknowledge terms or conditions before they can use the computer, such as an Acceptable Use Policy.
Create a banner
Create a plain text (.txt) or rich text (.rtf) document that contains your banner.
Choose File > Save, then enter PolicyBanner for the document name.
Copy the PolicyBanner file to the /Library/Security/ folder.
The next time you restart the computer, the banner will appear when you would normally see the login screen.
If your banner doesn't appear
If your banner doesn't appear, check the following.
Check FileVault
If you use FileVault full disk encryption The first login is performed to unlock the startup disk.
Check your permissions
In some instances, you may need to adjust the permissions on the PolicyBanner file.
For .txt or .rtf files, set the permissions on the Policy Banner file so that Everyone (Other) has read privileges:
sudo chmod o+r /Library/Security/PolicyBanner.txt
sudo chmod o+r /Library/Security/PolicyBanner.rtf
For .rtfd files, adjust the permissions so Everyone (Other) has both read and execute privileges:
sudo chmod -R o+rx /Library/Security/PolicyBanner.rtfd
Update the Preboot volume
If the policy banner still doesn't appear, update the Preboot volume:
diskutil apfs updatePreboot /
