According to the Securities and Exchange Commission ["SEC"] acceptance of transaction "success" fees by an advisor in a securities transaction [including, by definition, sales of non-public closely-held stock] mandates that practitioners in the M&A or capital raise industry must be Registered Representatives working under the supervision of licensed broker-dealers.  Unlicensed M&A practitioners may not receive "success fees" even for merely introducing the parties [also known as a Finder's Fee - see HallCap following].  The consequences to the Selling Client and Advisor associated with unlicensed security activity can be severe. Penalties can include retroactive deal rescission perhaps years after the transaction closed. The Seller may end up being responsible to refund the full value of the original transaction, plus costs and expenses.  As stated by the SEC, "If you will be acting as a 'broker' or 'dealer', you must not engage in securities business until you are properly registered. If you are already engaged in the business and are not yet registered, you should cease all activities until you are properly registered."   Also, an individual merely holding a series license is not sufficient.    The SEC's position regarding this is "If you hold a series license, you must be properly associated with a registered broker-dealer to effect securities transactions."