A single-family office is a private company that manages the investments, tax affairs, and administrative life of one family, and which in the United States is excluded from registering with the SEC as an investment adviser under the family office rule.
In plain terms
At a certain scale, a family stops buying financial services and starts employing them. The office is a real company with a payroll — a chief investment officer, a controller, a tax director, often an estate manager — and its only client is the family that owns it. It runs the portfolio, files the returns, administers the trusts, insures the houses, and settles the arguments. What distinguishes it from a wealth manager is not sophistication. It is that nobody outside the family pays for it, and nobody outside the family is served by it.
How it works
Before 2010, most family offices relied on the Investment Advisers Act’s exemption for advisers with fewer than fifteen clients. Dodd-Frank repealed that exemption, which would have forced thousands of purely private offices to register with the SEC. Congress instructed the Commission to write a replacement, and in June 2011 the SEC adopted Rule 202(a)(11)(G)-1.
The rule sets three tests, and all three must hold. The office may have no clients other than family clients — a defined category covering lineal descendants of a common ancestor no more than ten generations removed, their spouses, certain key employees, and family trusts and entities. It must be wholly owned by family clients. And it must be exclusively controlled by family members or family entities. A fourth condition sits alongside them: the office may not hold itself out to the public as an investment adviser. The SEC’s adopting release is explicit that in-laws related only through a spouse do not count as family members.
Note what the rule does not contain: a dollar threshold. There is no minimum size. An office that fails any of the tests loses the exclusion entirely and must register — with the SEC once regulatory assets reach $110 million, with a state regulator below that, per the Form ADV instructions.
The numbers
- Single-family offices worldwide, 2024: an estimated 8,030, up from 6,130 in 2019, per Deloitte’s Family Office Insights Series.
- Average assets under management: approximately $2.0 billion (Deloitte, 2024).
- Minimum size required by the SEC rule: none. The tests are ownership, control, and clientele.
- Generational reach of “family client”: lineal descendants of a common ancestor no more than ten generations removed (Rule 202(a)(11)(G)-1, adopted 2011).
- Registration threshold if the exclusion is lost: $110 million in regulatory assets under management for SEC registration; $100 million permits it.
- Jurisdiction: United States. Other countries regulate family offices under entirely different regimes, and several — Singapore and Hong Kong among them — compete for them with tax incentives.
What people get wrong
That the family office exclusion is a tax structure. It is not. Rule 202(a)(11)(G)-1 is a securities-law provision and confers no tax benefit whatsoever — it only means the office avoids SEC registration, compliance staff, and examination.
The tax question is separate and much less settled. A family office’s expenses are ordinarily investment expenses, which since 2018 have been non-deductible for individuals. The workaround is to argue the office is a genuine trade or business under § 162, which the Tax Court accepted in Lender Management LLC v. Commissioner (T.C. Memo 2017-246) because that office served family members whose interests were genuinely adverse to one another and charged them a profits interest. The case is frequently cited as a template; it is better read as a warning. Its reasoning turned on facts most family offices cannot honestly replicate — real clients with real conflicts, real fees, and a manager doing something other than tending one household’s balance sheet.
Related
Read more: Family Office: How the Very Rich Organize Their Lives and Money · Money Management: From Wealth Manager to Family Office · Wealth Levels: Life at $1M, $10M, $100M, and $1B
See also: Multi-family office · Accredited investor · Estate manager · Endowment model