Single Family Office vs. Multi Family Office: Which Model Fits (Part 2 of 5)

In Part 1 we asked whether a family needs a family office at all. If the answer is yes, the next question is which kind. There are two basic models: an office that works for one family, and an office that works for many. Between them sit several in-between versions, and the right choice depends less on prestige than on money, control, and the work that actually needs doing.

The main models

1. Single family office (SFO). A separate company that manages the financial and personal affairs of one wealthy family. It usually has its own staff, such as a chief executive, a chief investment officer, and accountants, and it is kept apart from the family business.
2. Multi family office (MFO). A company that manages the wealth of a group of families. Some grew out of a single family’s office; others were set up as commercial firms from the start. Either way, the idea is to spread costs across many clients.
3. Embedded family office. Family affairs are handled inside the family company, usually by its existing staff, often without a formal plan. Merrill warns that this model can mix personal and business expenses (its example is the company jet), create staff with divided loyalties, and complicate a sale of the business.
4. Virtual or outsourced family office. One or two people coordinate outside lawyers, accountants, and investment managers instead of employing a full team.
5. Multi-client family office. A lead family that takes on a few other families to share the cost of its office.

How many family offices are there?

Deloitte Private estimated that there were about 8,030 single family offices in the world in 2024, up from 6,130 in 2019, managing about $3.1 trillion. It expects about 10,720 offices and $5.4 trillion by 2030. North America had the most (about 3,180), followed by Asia-Pacific (2,290) and Europe (2,020).

Treat these as estimates. Family offices keep a low profile, and counts vary widely: one research firm that tries to identify them by name finds only about 2,700.

How much money does each model need?

There is no official threshold, and the sources disagree:

• A Deloitte guide notes that many in the industry cite about $100 million in investable assets as the starting point for a single family office.
• UBS suggests an embedded office below $250 million, a virtual office between $250 million and $1 billion, and a full single family office from about $1 billion.
• EY says a family generally needs at least $250 million for any family office, and $1 billion or more for a stand-alone, full-service one.
• Bernd Scherer of EDHEC Business School called the $100 million rule “grossly misleading.” In his view, the right minimum depends on costs, investment skill, and appetite for risk.

The honest answer is that the threshold is about cost relative to assets. A team that costs a few million dollars a year is a small share of $2 billion and a large share of $100 million. We look at those numbers in Part 3.

From one family to many

Several of the best-known multi family offices began as the office of a single family and opened up later, usually to share costs.

• Rockefeller. John D. Rockefeller, whose rise we followed in our Rockefeller series, set up his family office in 1882. According to The Wall Street Journal, it first opened its doors to outsiders in 1980, at first to foundations and endowments, and began taking other families in 1989. In 2018 it became part of Rockefeller Capital Management, owned by a Rockefeller family trust, management, and a fund of Viking Global Investors. The firm reported about $228 billion in client assets in mid-2026.
• Bessemer Trust. Henry Phipps, a partner of Andrew Carnegie in Carnegie Steel, founded it in 1907 to manage his family’s wealth. In 1974, “after much debate,” it opened to outside clients, in part to offset its considerable administrative costs. Today it reports about $250 billion under supervision.
• Pitcairn. The three sons of John Pitcairn Jr., a co-founder of PPG, organized the family’s holdings in 1923. In 1987, after the U.S. tax reform of 1986, Pitcairn began serving other families.

The pattern is the same each time: running an office for one family is expensive, and sharing it lowers the cost for everyone.

Strengths and weaknesses

A single family office offers the most control and privacy, and every service can be built around one family. Bank of America describes it as offering “the greatest degree of control.” The price is cost: UBS notes that it tends to have the highest internal costs. It also depends on a few people. Most offices are small: in Citi’s 2025 survey, 63% had six or fewer employees, so the loss of one key person can stop the work.

A multi family office shares costs and usually has a deeper team. EY notes that multi family offices often fall under specific regulation, while single family offices are much less regulated. The trade-off is less control, and confidentiality depends on the firm’s internal policies rather than on owning the office.

There is also the question of how the provider earns money. Family Office Exchange suggests watching for two red flags: owner-families paying less than other clients, and an office that serves as “a conduit for selling other investment products.” One question it recommends asking: “Do you earn annual revenue from any activities besides client fees?”

A fair caveat

The labels are loose. Many offices mix models, for example a small in-house team that outsources investment management. Much of the data comes from surveys of a few hundred offices that chose to respond, and some thresholds come from firms that sell the service. When the head of one multi family office told Fortune in 2025 that “$500 million is a good place to start” for a single family office, that view came from a provider of the alternative. Read every threshold, including the ones above, as a rule of thumb.

Five lessons to take away

1. Start with the job, not the structure. List what needs to be done, such as investing, tax, legal work, reporting, and family services, before choosing a model.
2. Treat thresholds as rules of thumb. $100 million, $250 million, and $1 billion are all quoted. Cost and complexity decide.
3. Sharing costs is not a step down. Bessemer, Pitcairn, and the Rockefeller office all opened to other families to spread expenses.
4. Ask how the provider gets paid. Fees paid by you are one thing; commissions on products sold to you are another.
5. Plan for people risk. In a small office, one departure can stop the work. Know who covers for whom.

Questions to bring to your advisors

Which tasks do we actually need covered, and which of them could be outsourced? What would a single family office cost us each year, and what would a multi family office charge for the same work? Who would make decisions if our key person left? These are questions to bring to your advisors, not advice.