Working on consumer loan audit. One of the questions is what the process for interest, discount and maturity date computations is. The response is that they are automated in the software. Validation when the software was installed regarding calculations was completed but this is not ongoing.

My question is whether there needs to be validations of calculations at a regular interval?

IMHO - if there is a change in the system software (update), bank computers or especially personnel, I would verify a few transactions. The time would be minimal, compared with the lookback if there was an issue and it came to light very much after the incident.