Customer Protection Rule (Rule 15c3-3)
SEC Rule 15c3-3, known as the Customer Protection Rule, requires registered broker-dealers to maintain physical possession or control of customer fully paid and excess margin securities, and to maintain a special reserve bank account holding a minimum amount of cash or qualified securities to satisfy net obligations owed to customers.
Rule 15c3-3 was adopted by the Securities and Exchange Commission in 1972, two years after the paperwork crisis of the late 1960s overwhelmed Wall Street brokerage operations and contributed to numerous firm failures. The core problem those failures exposed was that customers' securities and cash were commingled with firm assets, leaving investors with unsecured claims in bankruptcy proceedings. The Customer Protection Rule addresses this by establishing clear segregation requirements that transform customer assets into a protected pool largely insulated from the broker-dealer's own creditors.
The possession or control requirements in Rule 15c3-3(b) mandate that broker-dealers obtain and maintain physical possession or control of all fully paid customer securities within one business day of receiving them. Acceptable locations for control include the broker-dealer's own vault, a clearing corporation, a bank safekeeping account, or another broker-dealer that is itself carrying the securities under a control agreement. Securities lent to customers under approved margin agreements or used as collateral for bank loans within permitted arrangements are exceptions to the possession requirement.
The reserve formula under Rule 15c3-3(e) requires broker-dealers to compute, at least weekly, the net amount owed to customers across all accounts. The computation credits the firm for customer debits (amounts customers owe the firm on margin loans and similar items) and debits the firm for amounts owed to customers (credit balances, securities owed, and similar obligations). If the customer credit side exceeds the customer debit side, the firm must deposit the difference into a special reserve bank account by the close of the next business day. This account may hold only cash or specific US government or agency securities.
Compliance with Rule 15c3-3 is closely monitored by FINRA through its examination program and by the SEC's Office of Compliance Inspections and Examinations (now OCIE/EXAMS). Deficiencies in the reserve account or possession and control requirements are treated as serious violations. During the 2008 financial crisis and the subsequent Madoff scandal, the rule's provisions received heightened scrutiny, as Madoff's firm maintained its own clearing operations that circumvented normal third-party oversight of customer assets.
The Customer Protection Rule interacts with SIPC coverage. The Securities Investor Protection Corporation covers customer claims up to $500,000 (including $250,000 for cash) in the event of a broker-dealer failure. However, SIPC coverage is a backstop, not a substitute for segregation. Proper compliance with Rule 15c3-3 means that most customer assets should be recoverable directly from the estate without relying on SIPC insurance, which exists to cover the gap left when segregation fails.