A success fee is a contingent fee paid to a corporate advisor (or M&A advisor, broker, or boutique) on successful completion of a transaction, typically calculated as a percentage of transaction enterprise value. In Australian sub-$20M sell-side mandates, success fees are most commonly structured using the Modified Lehman or Double Lehman formula, often with a minimum success fee of $250,000 to $500,000.
Success fees are typically payable on transaction enterprise value rather than equity value, meaning the advisor is paid on the full deal size including any debt assumed by the buyer.