Hi Alison, there are bigger Box brains than mine in this forum so I may be corrected, but if you're an Admin you can set the default auto-expiration date for shared links by going to the Admin console>Enterprise Settings>Content and Sharing. The settings can be applied globally or on a per-folder basis. If you do make a change, I don't belive it will affect links already in place.

Thank you, Andy! Could you please confirm if we copy/paste the Box URL versus generate a shared link within Box, would this be a workaround from having to set the link to never expire? I.e., if we copy/paste a Box URL, would this never expire?
Hi Alison, i don't believe that will work. The great thing about links is that they continue to work even if the file/folder is moved whereas copying the URL would not.
Best, Andy.