A voluntary self-disclosure lowers the base penalty: from the applicable schedule amount to one-half of the transaction value in a non-egregious case, and from the statutory maximum to half of it in an egregious one. It is the largest lever a company controls after the conduct has happened, and it has to come before the regulator already knows.
OFAC decides this strictly. In the Danfoss case the company disclosed in October 2017, five months after its bank had told it about the problem, and OFAC held that its submission “did not qualify as a voluntary self-disclosure” because it already had the information. In the Fracht case the company’s own submission was treated the same way because US agencies already knew of the aircraft. See how penalties are decided.