No, there is no de minimis threshold for interest calculation errors for savings accounts in Regulation DD. The Truth in Savings Act formerly required restitution to customers for errors, but that provision was repealed in 2001.

We do recommend providing restitution to the affected customers, since a failure to pay interest as promised, even to a very minor extent, could be criticized by your examiners as a TISA violation and possibly as an unfair, deceptive or abusive act or practice (UDAAP).