Family Office Structures: Single-Family vs Multi-Family Office Models

The family office has become the gold standard of wealth management for ultra-high-net-worth families. But the term covers structures that differ enormously in cost, capability, and governance — from a lean three-person organisation managing a single family's assets to a large institutional operation servicing dozens of wealthy families. The fundamental choice every sufficiently wealthy family must make is between establishing their own single-family office (SFO) or joining or using a multi-family office (MFO). Understanding the trade-offs between these models is essential before making a decision that will shape how wealth is managed for generations. This guide examines both structures in detail, as of 2026.

What Is a Family Office?

A family office is a private organisation that manages the financial and personal affairs of one or more wealthy families. The "office" function encompasses investment management, tax planning, estate planning, philanthropy, family governance, and often lifestyle services (travel, property management, security, family education). It is distinguished from conventional wealth management by its breadth of scope, its orientation toward the family's specific objectives across generations, and its private, bespoke nature.

Family offices are not regulated in the same way as fund managers or financial advisers in most jurisdictions — though where they manage assets on behalf of third parties, relevant investment management regulation may apply. In the UK, family offices managing only a single family's assets are typically exempt from FCA regulation under the "family office exemption."

The Single-Family Office (SFO)

A single-family office is a private entity established by and for a single wealthy family. It employs staff, maintains physical premises (or operates remotely), and carries out the full range of financial and personal services the family requires.

What does an SFO do?

Services vary by family and by the complexity of the wealth, but typically include:

• Investment management: asset allocation strategy, manager selection, portfolio monitoring, performance reporting across all asset classes
• Tax compliance and planning: multi-jurisdiction tax returns, cross-border structuring, advance clearance applications, FATCA/CRS compliance
• Estate and succession planning: trust administration, beneficiary management, will drafting coordination, generational wealth transfer
• Cash management and banking relationships: treasury functions, currency management, private banking relationships
• Philanthropy: grant-making, charitable foundation management, impact investment oversight
• Family governance: family council support, family charter development, next-generation education
• Lifestyle services: travel, property, art and collectibles management, education and school placement, security
• Legal coordination: briefing external lawyers, managing contracts, intellectual property

Who should have an SFO?

The minimum practical threshold for establishing a standalone SFO depends on complexity and family preferences, but most practitioners suggest that families need at least £100–150 million in investable assets to justify the cost of a proper SFO operation. Below this threshold, the cost burden relative to assets managed becomes significant.

Cost is the primary constraint: even a lean SFO with a chief investment officer, a financial controller, a tax professional, and administrative support costs £500,000–£1 million per annum in staff costs alone, before premises, technology, professional services, and insurance. A fully staffed mid-size SFO might cost £2–5 million per annum.

For families at £250 million or above, this cost represents a relatively modest fraction of assets managed and is easily justified by the customisation, privacy, and control an SFO provides. For families at £50–100 million, the calculation is more marginal.

Advantages of the SFO

Total customisation. Every investment policy, reporting format, tax structure, and service is designed specifically for the family's objectives. There is no standardisation to accommodate other clients.

Privacy. The family's affairs are known only to the office's own staff and specific external advisers. There is no sharing of information with other families, no salesforce, and no product-pushing agenda.

Alignment of interests. SFO staff are employed by and accountable to the family. Unlike a wealth manager who earns fees and commissions from products, SFO staff have no financial incentive to recommend anything other than what is in the family's interest.

Integrated services. The SFO can act as the central coordinator of all external advisers — lawyers, accountants, investment managers, property managers — ensuring coherence and avoiding gaps that arise when professionals work in silos.

Institutional access. A well-established SFO with sufficient assets can access institutional-quality investment managers, fund terms, and co-investment opportunities that are unavailable to individual clients of wealth managers.

Disadvantages of the SFO

Cost. The fixed cost of operating an SFO is high and does not scale down proportionately if assets fall. The family bears the full cost regardless of market performance.

Key person risk. If the SFO chief investment officer or chief executive leaves, the family faces significant disruption. Replacing senior family office talent is time-consuming and expensive.

Operational burden. Running a business — even a family office — requires governance, HR, compliance, technology management, and professional liability management. Wealthy families are not always experienced business operators.

Limited diversification of expertise. A small SFO team cannot cover every specialist area with equal depth. An MFO pooling talent across more families can afford deeper specialisation.

The Multi-Family Office (MFO)

A multi-family office serves multiple wealthy families through a shared operational and professional platform. Some MFOs are independent, owned by their management team or by private equity. Others are part of larger financial institutions (private banks, accountancy firms, law firms) that have established dedicated family office divisions.

What does an MFO offer?

In principle, the same services as an SFO — investment management, tax, estate planning, philanthropy, governance, lifestyle services — but delivered across a client base of multiple families. The key difference is that the cost of staff, technology, and expertise is shared, reducing the per-family cost.

Who uses MFOs?

MFOs typically serve families with £10–150 million in investable assets — above the threshold where a private bank's standard wealth management offering feels insufficiently bespoke, but below the level at which a standalone SFO is cost-effective. Larger families may also use MFOs for specific functions (philanthropy administration, family governance facilitation) even where they have an SFO for core investment management.

MFOs range in quality from boutique, genuinely relationship-driven operations serving a small number of families to large institutional organisations (some of which have grown to the point of behaving like private banks). The founding spirit of the MFO — bespoke, conflict-free service modelled on the SFO experience — can be diluted as the organisation grows and the cost-sharing logic demands volume.

Advantages of the MFO

Lower cost. For families that cannot justify SFO costs, the MFO provides a more cost-efficient route to comprehensive, integrated wealth management. Fees typically represent 0.5–1.5% of assets under management per annum, including a range of services.

Breadth of expertise. MFOs with a substantial client base can afford specialists in areas — private market investing, philanthropy, alternative assets, multi-jurisdiction tax — that a small SFO could not employ independently.

Institutional relationships. Larger MFOs carry buying power with investment managers, custodians, and other service providers, accessing terms and products unavailable to smaller clients.

Infrastructure. Technology platforms, compliance systems, and operational processes are maintained and upgraded across the client base, benefiting all families without individual technology investment.

Continuity. An MFO does not depend on a single family's continued engagement for its survival. Staff retention, succession planning, and operational continuity are managed at the firm level, reducing key person risk for any individual family.

Disadvantages of the MFO

Conflicts of interest. An MFO that takes referral fees from investment managers, earns placement fees from fund managers, or has proprietary products may have conflicted interests. True MFOs should be fee-only or fee-transparent; always investigate the fee model before engaging.

Less bespoke than an SFO. Standardisation that enables cost sharing limits the degree of customisation. Reporting formats, investment approaches, and process flows are designed for multiple families rather than one.

Privacy concerns. Family information is known to MFO staff who also serve other families. While professional standards require strict confidentiality, the risk of inadvertent information sharing is greater than in a private SFO.

Service dilution as the firm grows. MFOs that grow rapidly may compromise the relationship quality that attracted clients in the first place. Reviewing the client-to-adviser ratio and the MFO's growth trajectory is important due diligence.

Hybrid Structures: The "Virtual" Family Office

A third model has emerged for families that want the coordination and bespoke nature of an SFO without the full employment burden: the "virtual" or "embedded" family office. In this model, a family appoints an external family office director or chief of wealth — typically an experienced private wealth professional — who coordinates a network of specialist external advisers (investment manager, tax adviser, lawyer, trust administrator) on behalf of the family.

This model provides a single point of accountability without employing a full team. It is cost-effective for families at £20–100 million and can scale as needs evolve. The risk is that the quality of the network depends heavily on the skill and network of the individual coordinator.

Making the Choice: A Framework

The right model depends on several factors:

Factor	Favours SFO	Favours MFO
Asset level	£150m+	£10–150m
Complexity	Very high (multi-jurisdiction, many entities, trust structures)	Moderate to high
Privacy priority	Absolute	High but shared
Family operational appetite	Comfortable managing a business	Prefer to delegate to specialists
Specialist needs	Standard family office services	Niche expertise important
Budget	Can justify £1m+ per annum fixed costs	Prefer percentage-based costs

How Global Investments Can Help

Global Investments advises wealthy families at all stages of the family office journey — from assessing whether an SFO or MFO is appropriate, to identifying reputable MFOs suited to specific family needs, to designing the governance structure for a new SFO. Our international perspective is particularly relevant for families spread across multiple jurisdictions, where family office structures must account for the regulatory, tax, and operational requirements of each country in which family members reside.

We work alongside families to ensure that whichever model is chosen, the investment philosophy, governance framework, and succession planning are coherent — so that the family office serves not just the current generation but those that follow.

This guide is for general information only and does not constitute financial or investment advice. Family office structures and costs vary considerably; all figures are indicative. All information reflects our understanding as of 2026. Always seek professional advice specific to your circumstances and objectives.