Do I Need a Family Office? Every Model and What It Costs

This guide is for founders and families with roughly €5M to €100M+ who are asking whether they need a family office. The conclusion: you need the six functions a family office performs, not necessarily the institution. Below the single-family office threshold, a multi-family office, an outsourced set-up or a coordination layer above your existing banks can run them, at a fraction of the cost. It also compares a private bank, an independent family office advisor and a multi-family office, and sets out what each model costs a year.

Founders who reach real wealth eventually collide with the family-office question, and they tend to mishandle it in one of two opposite ways. Both feel sensible from the inside. Both end up in the same place.

The first is deferral. They picture a real family office as a full institution: a chief investment officer, a chief financial officer, in-house legal, a compliance function, and the several hundred million it takes to carry all of it. They run the maths, conclude they are not at that scale, and keep managing a growing pile of complexity with the same informal arrangement they have been improvising for years.

The second is mislabelling. They have a tax advisor, an investment manager, an accountant, and a folder somewhere. They call the whole thing a family office because, at their level of wealth, the label feels earned. What they actually have is a set of specialists who never speak to one another, each accountable to a different institution, with the principal quietly holding the entire picture together in their own head.

Neither instinct is wrong on its own. But they converge on the same result: wealth that photographs well and behaves badly, orderly on the surface and improvised underneath.

The minimum viable family office dissolves both mistakes at once. It is not a single-family office with most of the staff stripped out. It is the smallest set of functions that genuinely delivers what a family office is for, and most founders sit closer to it than the deferrers fear, and further from it than the mislabellers believe.

Do I need a family office?

There is no legal or wealth minimum for a family office. The test is complexity: how many custodians, entities, jurisdictions and generations your wealth spans. Below the single-family office threshold, the six functions a family office performs can run through a multi-family office, an outsourced or fractional set-up, or a coordination layer above your existing banks.

A family office is the structure that coordinates a family’s wealth across its banks, entities and advisors. A dedicated one, owned by one family, is a single-family office, and Rankia’s Spain guide, updated in August 2026, puts its realistic threshold at €20–30M. Most founders who ask the question sit below that line. For them the answer is a choice of model, not a yes or a no. The rest of this piece sets out the models, what each one costs, and the six functions any of them has to deliver.

What a family office actually does

Of the three words in minimum viable family office, the first two are the easy ones. It is the third that everyone gets wrong, so that is where to start.

A family office exists to do a single thing: coordinate complex wealth. Managing the investments belongs to the investment manager; filing the taxes to the accountant; drafting the structures to the lawyer. The office is the layer that sits above all of them: the one that carries the whole picture, keeps every specialist working from the same facts, and makes sure decisions are chosen rather than backed into.

Remove that layer and nothing obvious breaks. Each specialist keeps performing: the portfolio is managed, the returns filed, the structures kept current. What disappears is the connective tissue between them. Nobody is blind to their own slice; everybody is blind to everyone else’s. And it is in those blind spots, not inside any single mandate, that wealth quietly bleeds.

It looks like this. A tax position left on the table because the investment side and the tax side never spoke. A portfolio that slid past the family’s real risk tolerance because no written policy existed to check it against. A principal losing hours every week to operational questions that should have been settled three levels below them. No statement ever flags any of it. All of it compounds. (We unpack the broader discipline this sits inside in What is wealth advisory and, in long form, in Private Wealth Advisory Explained.)

Family office options by complexity, from €5M to €100M+

The mistake is to read the models below as a price ladder you climb. They describe how the work is staffed. The minimum viable family office describes whether the work gets done at all, and you can have it in any of them. The numbers ① to ⑥ refer to the six functions set out further down.

Starting wealth for the private bank, multi-family office and single-family office rows comes from Rankia’s Spain guide, updated on 25 August 2026. No survey publishes a threshold for outsourced set-ups or coordination layers. Who manages the money, who pays whom and what each model costs a year are set out in the two comparisons below.

The single-family office model is still growing. Deloitte Private counts 8,030 single-family offices worldwide in 2024, up 31% from 6,130 in 2019, and projects 10,720 by 2030. Most successful founders are nowhere near the threshold that justifies one, and they do not need to be. They need the functions, not the institution.

Private bank vs independent family office advisor vs multi-family office: which is best for a family with €20M–€100M?

At €20M–€100M, it depends on what is missing. If one bank holds almost everything, a private bank can be enough. If you want one firm to run the investments, a multi-family office fits. If several good banks hold the money and nobody sees or governs the whole, an independent family office advisor, paid only by the family, closes that gap.

An independent family office advisor designs and coordinates the functions of a family office without managing money or selling products. It sits above the banks, managers, lawyers and accountants the family already uses. That is the model PWA works in, so read the comparison knowing which column is ours. (Whether you need any advisor at this level is the subject of Do I need a private wealth advisor?)

How to choose at €20M, €50M and €100M

At €20M, a single-family office is hard to justify. Rankia’s minimum fixed cost of €300,000–620,000 a year equals 1.5–3.1% of the assets, more than a good multi-family office charges. Wealth at this level is often one sale or one operating company, held at one or two banks and a holding company. If one bank really does hold almost all of it, a private bank with a clear written mandate can be enough. Once a second bank, property or a second jurisdiction arrives, the bank’s view stops at its own accounts, and the choice is between handing the investments to a multi-family office or keeping the banks and adding coordination above them.

At €50M, the gap between institutions is usually at its widest: three or four custodians, several entities, often two jurisdictions and a next generation coming of age. On Rankia’s figures, a single-family office’s minimum fixed costs now equal 0.6–1.2% of assets, still above a typical multi-family office fee. A multi-family office works if the family wants to delegate investment management and accepts that the firm managing the money also reports on how well it did. If the family would rather keep its banks and make them compete, the independent model writes the investment policy statement they work to, runs consolidated reporting across all of them and compares their fees. That is the work of our investment and wealth architecture and administrative back office services.

At €100M, a single-family office becomes reasonable on cost. Rankia’s minimum fixed costs fall to 0.3–0.6% of assets, and J.P. Morgan’s 2026 survey puts the average annual cost of offices with $250M or less at $0.9M. Building one is still a decision about control, privacy and workload, not a reward for crossing a figure. Even large offices buy specialist work in: UBS’s 2026 report finds that 75% outsource legal services and 59% outsource tax planning. At €100M the question is less which model to pick than who, inside it, owns the whole picture.

In our work with families in this band, the banks are rarely the problem; most families have competent private bankers. What is missing is a party with no product to sell who reads every statement against the same policy. Whichever model you choose, make sure someone in it has that job, in writing.

Single-family office vs multi-family office vs outsourced family office: what does each cost annually, and when is each worth it?

A single-family office costs €300,000–1M a year in fixed costs in Spain (Rankia, 2026), and surveyed offices with up to $250M average $0.9M (J.P. Morgan, 2026). A multi-family office charges 0.3–0.8% of assets or €15,000–60,000 fixed. An outsourced family office has no published benchmark: it costs the sum of the functions you contract.

Published cost data comes almost entirely from surveys of large single-family offices, and those surveys report in US dollars. We quote them as published and have not converted them to euros. The euro figures come from Rankia’s Spain guide, updated on 25 August 2026, which also breaks a minimum single-family office into its cost lines.

Three patterns hold across the surveys. Staff are the largest cost: two-thirds (66%) of pure running costs in UBS’s 2025 report, and still the largest factor in its 2026 report, where pure operating costs are 53% of total spend and the share spent on IT has fallen. Cambridge Associates notes that an in-house chief investment officer, two investment analysts and a data analyst alone can top $1M a year in compensation, benefits and overhead. Scale matters: Campden Wealth’s European offices with more than $1bn of assets spend 36 bps a year, against 105 bps for those below $0.5bn. A family with €20M that builds its own office pays the small-office rate on a fraction of the assets. Even large offices outsource: in UBS’s 2026 report, 75% buy in legal services, 59% tax planning and 52% cybersecurity, while 75% keep consolidated financial reporting in-house. The function they keep is the one that holds the whole picture.

What you pay for anyway

Whichever model you choose, some bills do not go away. Custodians charge custody and transaction fees. Funds carry management fees, and some still pay retrocessions to the bank that sold them. Accountants file the returns of every entity, and lawyers keep the structures current. UBS’s 2025 report shows how large this layer is: asset-management costs are 21% and banking-related fees 10% of total family office spend, on top of the 57% the office itself costs (UBS’s projection for 2025). A family office does not remove these bills. Its job is to make them visible and comparable.

When each model is worth it

• Private bank alone is worth it while one bank holds almost everything, there are few entities and the family lives in one jurisdiction.
• A multi-family office is worth it when the family wants one firm to run the investments, most of the wealth is liquid, and the all-in cost, including the fees of the underlying funds, is lower than what the banks charge today. Ask who checks its results.
• An outsourced or fractional family office is worth it when specific functions are missing, typically bookkeeping, reporting or tax compliance, and the rest already works. It pays off only if someone coordinates the providers; otherwise it adds more slices to a picture nobody holds. For a lean family office that still runs on spreadsheets and inboxes, family office on Excel and email sets out what to keep, what to move and what to outsource.
• A coordination layer above the existing banks is worth it when the banks are competent but nobody owns the whole: several custodians, several entities, more than one jurisdiction, and a family that wants oversight without moving the money to a new manager.
• A single-family office is worth it when its fixed costs fall below about 0.6% of assets, which Rankia places above €50–100M, and when there is enough recurring work, such as direct investments, many entities or several households, to keep a team busy. It still needs one person inside it who owns the whole picture.

The six functions that make it real

A minimum viable family office does six jobs. Most of them cost no salary at all. None of them happen by accident; each one has to be chosen on purpose.

1. A written purpose, and who decides

Function one is purpose, scope, and decision rights, written down rather than understood in passing. What is this capital ultimately for, and on what horizon? Which decisions live inside the office, and which deliberately sit outside it? Who can sign off on what, and at what size? An office without those answers does not stay neutral; it slides into a request-driven desk that keeps absorbing whatever lands on it, and the principal becomes the fallback signature on every decision nobody else was cleared to make.

2. One true picture of what you own

Function two is a single consolidated view: one current, accurate account of everything owned, across every bank, entity, asset class, and liability. At this tier the picture almost always exists in fragments: the investment advisor holds one figure, the accountant a different one, the principal a third from memory. When those numbers disagree, every decision after that rests on a guess. Consolidated reporting and the operations in function four are the core of our administrative back office work. Whether that view needs software, and who should choose it, is covered in family office technology. There is a blunt way to test whether you have solved it:

3. One person who owns the whole

Function three is coordination, and no software solves it: it needs a named human. Someone whose actual job is to walk into every advisor meeting already holding the integrated view, move information between the specialists, close the loop on what was agreed, and keep the principal’s calendar reserved for judgement rather than admin. In informal setups this is the role that almost never exists, and its absence is the costliest of the six. Each advisor is doing their part; no one is owning the sum. A coordinator doesn’t displace the specialists. They multiply them, by making sure all of them pull from one picture toward one outcome.

4. Operations you can actually trust

Function four is operational discipline: the plumbing. Written procedures for how money actually moves. A rule for who may release a payment, up to what size, against what proof. A calendar holding every tax and filing deadline across every entity, so none of them survives only in an inbox. A monthly close that reconciles the accounts and confirms nothing slipped through. It is the least glamorous of the six and the one nobody notices until it fails, and when it fails, the loss dwarfs the modesty of the control that would have caught it. Fraud, missed filings, rogue payments, compliance breaches: these are overwhelmingly failures of process, not failures of character.

5. A policy that governs the portfolio

Function five is investment governance: not a strategy, and not the name of a good manager in your contacts. It is a written policy: what this money must achieve, how much risk is tolerable, how much has to stay liquid at all times, and what is simply off the table. Leave those blanks empty and the manager fills them for you, out of their own judgement. They may even fill them well, but you have no benchmark to hold them to and no record of why anything was done. The policy doesn’t run the portfolio. It sets the rules for whoever does. (How we set that policy and oversee managers without managing money is described under investment and wealth architecture; on disciplined investing versus chasing a story, see Innovation vs experimentation.)

6. A plan for the principal’s absence

Function six is continuity, the question almost everyone postpones until it can no longer be postponed: if the principal went dark for two weeks starting tomorrow, would anything keep running? Who can reach the accounts? Who releases payments? Who phones the advisors and drives the monthly close? Those answers have to be written down while they are still hypothetical, because the day you need them is the day no one can ask.

This is not an edge case; it is the sector’s rawest nerve. J.P. Morgan’s 2026 survey finds that 86% of family offices lack a clear succession plan for key decision makers, and UBS’s 2026 report finds that only 35% have a defined succession plan for the family office itself. An office that runs purely because one person carries it all in their head is not an operating layer. It is a single point of failure in a good suit. (We go deeper on the human side of this in Family governance and the next generation.)

Four out of six functions is not a smaller family office

Look at six functions and the natural instinct is to bank the ones you already have as progress. They don’t count that way.

Pair flawless investment governance with no consolidated view and you make immaculate decisions about a picture you cannot actually see. Hire a coordinator but skip written decision rights and you’ve appointed someone to coordinate with no authority behind them. Document every operation but omit a continuity plan and you stay spotless right until the day resilience is required, and on that day you have none.

The six interlock; that is the entire point. Minimum is a line you clear, not a menu you order from. And the price of not clearing it is anything but abstract. In the United States alone, Cerulli Associates expects $124 trillion to change hands through 2048, much of it through succession, the moment unstructured wealth tends to fail. High-net-worth and ultra-high-net-worth (UHNW) households, just 2% of all households, account for more than half of it: $62 trillion.

The minimum viable family office is just the moment all six exist together, each at its plainest workable form, and the structure finally stands on its own. For most founders that line sits nearer than they fear, and further than their current arrangement has actually reached.

You build a family office; you don’t buy one

You cannot buy a family office off a law firm’s shelf or take delivery of one from a consultant. It is something you practise, not something you acquire: a decision to run your wealth with the same seriousness and design you brought to building whatever produced it. Founders already have that muscle. They used it once, on the thing that generated the wealth. A family office is the same instinct, turned toward what comes after.

For years, that is the work we have done at PWA: designing and running an independent operating layer above a family’s banks, managers, lawyers and accountants, so that someone, finally, is responsible for the whole picture. Not another portfolio. Not another product. PWA does not manage money, hold mandates, take commissions or give regulated investment, tax or legal advice. We are paid by the family, and only by the family. In our work, the function most often missing is the third: everyone owns a slice and nobody owns the whole. A founder, four banks, eleven entities, no single view shows what that looks like in practice.

Which leaves the one question every founder at this tier should be able to answer in a sentence, and most cannot:

If the self-diagnosis left you short of six, the fastest first step, before you choose any model, is a written second opinion on how your wealth is organised today.

Questions we hear

What is a minimum viable family office?

A minimum viable family office is the smallest set-up that does what a family office exists to do: coordinate complex wealth. It is six functions performed on purpose: written decision rights, one consolidated view, one coordinator, documented operations, a written investment policy statement and a continuity plan. It needs intention more than headcount, and it fits inside any staffing model.

Do I need a family office with €20 million?

Usually not a single-family office. Rankia’s 2026 Spain guide puts the realistic threshold at €20–30 million, where €300,000 to €620,000 of minimum fixed costs equal 1.5–3.1% of assets a year. With €20 million you still need the six functions, and a multi-family office, an outsourced set-up or a coordination layer can run them for less.

What is the minimum net worth for a family office?

There is no legal minimum. Published entry points depend on the model: Rankia’s 2026 Spain guide cites €300,000 to €1 million for private banking, €2–5 million for a multi-family office and €20–30 million for a single-family office. The better test is complexity: how many custodians, entities, jurisdictions and generations the wealth spans.

How much does a family office cost per year?

It depends on the model. Rankia’s 2026 Spain guide puts a single-family office at €300,000 to €1 million of fixed costs a year and a multi-family office at 0.3–0.8% of assets or €15,000–60,000 fixed. J.P. Morgan’s 2026 survey puts offices with up to $250 million at $0.9 million a year, and Europe and the Middle East at $2.5 million.

Private bank, independent family office advisor or multi-family office: which is best for €20M–€100M?

It depends on what is missing. A private bank is enough while one bank holds almost everything. A multi-family office suits families that want one firm to run the investments. When several banks hold the money and nobody sees the whole, an independent family office advisor, paid only by the family, coordinates them without managing money.

Is a single-family office cheaper than a multi-family office?

Not below about €50–100 million. Rankia’s 2026 Spain guide puts a single-family office’s minimum fixed costs at €300,000–620,000 a year, equal to 1.5–3.1% of assets at €20 million and under 0.6% only above €50–100 million. A multi-family office charges 0.3–0.8% of assets or €15,000–60,000 fixed, so below that line it is usually cheaper.

What does an outsourced family office cost?

No survey publishes a reliable benchmark, because an outsourced or fractional family office costs the sum of the functions you contract. Rankia’s 2026 Spain guide prices the in-house versions: €120,000–250,000 for an investment director, €80,000–150,000 for senior tax and legal, €40,000–80,000 for back office and accounting, and €30,000–80,000 for technology.

What is the difference between a single-family office, a multi-family office and an outsourced family office?

A single-family office is a dedicated team serving one family. A multi-family office shares one team and its infrastructure across several families, which lowers the entry point. An outsourced or fractional family office contracts the functions out to specialists and part-time staff. All three describe how the work is staffed, not whether the six functions actually get done.

What functions must a family office perform?

Six: a written purpose with decision rights; consolidated visibility of every asset, entity and liability; one person who holds the whole picture and coordinates the specialists; documented operations with payment controls and a deadline calendar; a written investment policy statement; and a continuity plan for when the principal is unavailable. Each one depends on the others to work.

When should a founder set up a family office?

When complexity arrives, not when a net-worth figure does. The signals cluster around change: selling a business, an inheritance, a move of country or tax residence, accounts at several banks with no single view, or property, operating companies and private deals held at once. Feeling financially successful but operationally exposed is the clearest signal.

Why do families lose control of their wealth even with good advisors?

Because good advisors working in isolation are not coordinated wealth. The investment manager, accountant and lawyer each do their job, but nobody holds the complete picture or makes sure they work from the same facts. The cost sits in the gaps: the tax saving missed, the portfolio that drifted from the family’s risk tolerance, the succession nobody structured.

Sources

All pages opened and checked on 19 October 2026. Survey figures are quoted in US dollars as published; none has been converted.

• Rankia (Miguel Arias), “Family office: qué es, cuándo tiene sentido y qué cuesta en España”, updated 25 August 2026. Supports: entry points of €300K–1M (private banking), €2–5M (multi-family office) and €20–30M (single-family office); annual costs of 0.8–1.5%, 0.3–0.8% or €15,000–60,000 fixed, and €300,000–1M fixed; minimum single-family office cost lines of €120,000–250,000 (investment director), €80,000–150,000 (senior tax and legal), €40,000–80,000 (back office and accounting), €30,000–80,000 (technology) and €30,000–60,000 (operating expenses), totalling about €300,000–620,000; 1.5–3.1% of assets at €20M; below 0.6% above €50–100M. The 0.6–1.2% at €50M and 0.3–0.6% at €100M are our arithmetic on the €300,000–620,000 minimum. rankia.com
• UBS, “Global Family Office Report 2025”, 21 May 2025 (317 family offices, average family net worth $2.7bn). Supports: average pure running cost of 41.1 bps in 2024; 41.8 bps projected for offices with $100–250M; staff at 66% of pure cost; 2025 cost split of 57% pure cost, 21% asset management, 10% banking-related fees. advisors.ubs.com
• UBS, “UBS Global Family Office Report 2026” media release, 28 May 2026 (307 family offices). Supports: only 35% have a defined succession plan for the family office itself. ubs.com
• UBS, “Global Family Office Report 2026”, full report, May 2026, section 7 (“Costs, staffing and governance”). Supports: pure operating costs at 53% of expenditure, staffing the largest factor, a falling IT share; 75% outsource legal services, 59% tax planning and 52% cybersecurity; 75% keep consolidated financial reporting in-house. ubs.com
• Campden Wealth with HSBC Global Private Banking, “The European Family Office Report 2024”, 2024. Supports: $2.6M and 105 bps for offices under $0.5bn (average $249M); 36 bps above $1bn; often under $1M below $100M. campdenwealth.com
• J.P. Morgan Private Bank, “2026 Global Family Office Report”, 2 February 2026 (333 single-family offices, average net worth $1.6bn). Supports: 86% lack a clear succession plan for key decision makers; average operating costs of $0.9M for offices with $250M or less, $2.5M in Europe and the Middle East and above $6.6M for offices with more than $1bn. privatebank.jpmorgan.com
• Deloitte Private, “Defining the Family Office Landscape, 2024”, 2024. Supports: 8,030 single-family offices in 2024, up 31% from 6,130 in 2019; 10,720 projected by 2030. deloitte.com
• Cerulli Associates, “Cerulli Anticipates $124 Trillion in Wealth Will Transfer Through 2048”, 5 December 2024. Supports: $124 trillion through 2048; $62 trillion from HNW and UHNW households, 2% of all households. cerulli.com
• Cambridge Associates, “Determining the Right Price: A Wealth Management Cost Framework for Families”, 27 April 2023, updated 23 October 2023. Supports: an in-house chief investment officer, two investment analysts and a data analyst can top $1,000,000 a year in compensation, benefits and overhead. cambridgeassociates.com
• Family Wealth Report (Charles Paikert), “Family Wealth Alliance Pricing Study: Raise Fees Or Risk Losses”, 9 December 2024, on the Family Wealth Alliance study “Fees and Pricing in Family Wealth”. Supports: multi-family offices’ average minimum annual fee of $100,000, up from $65,000 in 2015; 70% charge a retainer as well as an asset-based fee. familywealthreport.com
• European Parliament and Council, Directive 2014/65/EU (MiFID II), 15 May 2014, Article 24(7)(b) and 24(9). Supports: firms that describe their investment advice as independent may not accept and retain third-party fees or commissions; other firms may receive them under disclosure and quality-enhancement conditions. eur-lex.europa.eu

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Pedro Souto is the founder of PWA — Private Wealth Advisory. He works with UHNW founders, families, and single-family offices to build an independent operating layer around complex wealth — combining markets, analytics, technology, and governance to turn fragmented advice into one coherent picture, and to make someone, finally, responsible for the whole of it.