Merchant banker underwriting rules: only commission allowed, underwriting capped by liquid net worth, and subscription required when called. Merchant bankers acting as underwriters may receive only commission or brokerage and no other direct or indirect benefit; their aggregate underwriting obligations are limited to twenty times their liquid net worth, with compliance timelines for existing registrants; and if called under an underwriting agreement they must subscribe to the securities prior to finalisation of the basis of allotment.