I have a customer that is on account analysis. Am I violating any regulation if I take the net earnings credit (after service charges, bank fees, etc.) and apply the leftover credit to the customers expenses, provided they provide me with an invoice?

"apply the leftover credit to the customers expenses"

What expenses?

If there is leftover credit for that statement cycle and there are fees that were not included in the analysis and covered by the EC this would be a decision for the account relationship manager (if there is one). Depending on the relationship with the customer will depend on what fees are usually covered.

Any "leftover" EC is normally not carried over to the next statement cycle as the EC is calculated using the total ACB of the # of accounts that may be grouped for a composite analysis versus a single account(minus reserves)for the current statement cycle.