The best recent benchmark is UBS's Global Family Office Report 2025, which surveyed 317 family offices with an average family net worth of $2.7 billion. Those offices reported that the pure cost of running the office (people, systems, premises, legal, and research) averaged 41.1 basis points of assets under management in 2024, slightly above the 40.3 basis points they had budgeted.

That figure excludes the money spent on investment managers, banks, and external legal structures. In UBS's data, those categories made up about 43% of total spending, so the full bill is meaningfully higher than the running cost alone.

What does that look like in dollars?

UBS broke the 2025 running-cost projections out by the size of the office.

Running cost only: excludes investment management, banking, and external structure fees. Dollar figures are the percentage applied to the bottom of each range, for illustration.

Two things stand out. First, costs barely improve between $100 million and $1 billion; real economies of scale show up only above $1 billion. Second, complexity costs more. Offices whose families also own an operating business projected 44.9 basis points, against 33.0 for those without one. Offices serving second and later generations projected 44.0, against 36.8 for first-generation offices.

Where does the money go?

Mostly to people. In UBS's survey, the pure cost of running the office broke down like this:

Projected 2025 split, UBS Global Family Office Report 2025.

The average office in the survey employed 12 people. That is the core of the economics: a family office is mostly a team, and a team costs about the same whether the portfolio is up or down.

Why does the math get hard below $100 million?

Because a family office's biggest costs are fixed, the cost as a percentage of assets rises quickly as assets fall.

Take a single senior hire. In Heidrick & Struggles' 2025 compensation survey, U.S. family office chief investment officers reported a median cash base salary of about $560,000, before bonus.

Base salary only. Excludes bonus, benefits, other staff, systems, and premises.

At $50 million, one salary costs more than the entire running budget of an average office in the UBS survey, measured as a share of assets. And a CIO alone is not a family office: someone still has to run reporting, administration, tax coordination, and governance.

What are the alternatives?

Families that want family-office structure without family-office overhead generally choose among three models:

• Multi-family office. Several families share one team and one set of systems. Costs are spread out, but families are usually clients of the firm rather than owners of their own structure.
• Outsourced or virtual family office. A coordinator oversees a network of external specialists. Flexible, but quality depends on who is quarterbacking.
• Dedicated office on a shared platform. Each family owns its own family office entity, board, and governance, and the platform supplies the staff and systems underneath. This is the model 2SIX Partners uses.

What should a family compare?

Cost in basis points is only part of the decision. Before choosing a structure, a family should be able to answer:

1. Who owns the structure? If the relationship ends, does the governance stay with the family?
2. Who is accountable for the whole balance sheet? Not each piece, the whole.
3. What is fixed and what is variable? A standalone office is mostly fixed cost; shared models can match cost to the services used.
4. Who will run it in 10 years? Key-person risk is real in a small standalone office.
5. What does the next generation inherit? A structure they understand and can govern, or a staff they did not choose?

The difference is ownership. A single family office is a company the family owns, staffed by people the family employs, working only for that family. A multi-family office is a firm that serves many families from one team; each family is a client.

Most of the practical differences, including cost, control, privacy, and what happens over generations, follow from that one fact.

How do they compare?

General comparison. Individual offices and firms vary widely.

When does a single family office make sense?

An SFO makes sense when the family wants full control, has enough complexity to keep a team busy, and has enough wealth that a team's fixed cost is a reasonable share of assets.

That last point is the hard one. In UBS's Global Family Office Report 2025, the cost of running the office averaged 41.1 basis points of assets in 2024, and staff were 67% of that cost. Because salaries don't fall when assets do, a standalone office gets proportionally more expensive the smaller it is. We walk through the numbers in How Much Does It Cost to Run a Single Family Office?

When does a multi-family office make sense?

An MFO makes sense when a family wants professional coordination, reporting, and governance support without building an organization. It is also a common bridge: families often start in an MFO and move to an SFO as wealth and complexity grow.

The questions to ask an MFO are mostly about control:

• Who owns the governance documents, reporting history, and entity records?
• If we leave, what stays with us?
• Who will actually work on our family, and how many other families do they serve?
• Is the firm paid by anyone other than us?

What is a hybrid family office?

A hybrid gives each family its own family office, with its own entity, board, and charter, while a shared platform supplies the staff, systems, and reporting underneath. The family owns the structure; the platform runs it.

This is the model 2SIX Partners uses. The aim is the ownership and governance of a single family office, without carrying a full team's fixed cost alone.

What doesn't change with the structure?

Whichever model a family chooses, two things stay the same:

1. The attorney and CPA still matter. A family office, single or multi, coordinates legal and tax work; it does not replace the professionals who are responsible for it.
2. Governance is the real asset. The office is the machinery. The family's charter, decision rights, and preparation of the next generation determine whether the wealth lasts. See Family Governance.