Let's say a business has been exempt from CTR filings for ten years. You have all the biennial renewals that were required once upon a time, each annual documentation of account review, anything and everything else. Does all of this need to stay in the file for as long as the account is exempt, or can we just have forms and documentation from the most recent annual review? Wanted to see what other bankers do when you have customers who are exempt year to year and have been for many years.

I'd use the general recordkeeping rule in the regulation and retain the most recent five years' documentation for the exemption.

Retention for these documents is five years. I, personally, keep everything, but that's because I deal with a manageable number of exemptions and everything is kept electronically. I have an active folder for each exempt person and add my annual review to it every year. When the exemption is revoked or the account is closed, I simply move the entire folder to an inactive folder.