--- title: "Family offices | Altss Taxonomy" description: "A family office is a private organisation that manages the investments, and often the wider financial affairs, of one wealthy family or of several. It is…" canonical: "https://altss.com/taxonomy/family-offices" --- Topic hub # Family offices A [family office](https://altss.com/glossary/family-office) is a private organisation that manages the investments, and often the wider financial affairs, of one wealthy family or of several. It is a kind of allocator, not a legal form. This hub covers the types of family office, their US regulatory treatment, the structures families invest through, and how family offices invest in private markets. Types come first: the [single-family office](https://altss.com/glossary/single-family-office) and the [multi-family office](https://altss.com/glossary/multi-family-office). A regulation section follows with the US [family office rule](https://altss.com/glossary/family-office-rule) and the [registered investment adviser](https://altss.com/glossary/registered-investment-advisor); the rule's scope and conditions are set out in its own entry. A final section covers how families hold and make investments: [holding companies](https://altss.com/glossary/holding-company), [direct investment](https://altss.com/glossary/direct-investment), [co-investment](https://altss.com/glossary/co-investment) and the [investment committee](https://altss.com/glossary/investment-committee). Not in this hub: pensions, endowments, foundations and other institutional allocators, which are in [Institutional investors](https://altss.com/taxonomy/institutional-investors). Private banks and wealth managers appear only as advisers to families. How Altss classifies family offices is set out in its classification standard, linked below. Publisher: Altss LLCPublished 2026-01-07Content modified 2026-10-02 9 concepts · 1 framework ## Reference index Definition: [Family Office](https://altss.com/glossary/family-office) — A family office is a private organisation that manages the investments and often the wider financial affairs of one wealthy family (a single-family office) or of several (a multi-family office); it is a kind of allocator, not a legal form. ### Types 2 concepts - [Single-Family Office (SFO)](https://altss.com/glossary/single-family-office) A single-family office (SFO) is a private organisation owned and controlled by one family that manages that family's investments and related financial affairs and has no outside clients. - [Multi-Family Office (MFO)](https://altss.com/glossary/multi-family-office) A multi-family office (MFO) is a firm that provides investment management and family-office services to several unrelated families, either allocating their capital with discretion or advising families who decide for themselves. ### Regulation 2 concepts - [SEC Family Office Rule (Rule 202(a)(11)(G)-1)](https://altss.com/glossary/family-office-rule) The Family Office Rule is Securities and Exchange Commission (SEC) Rule 202(a)(11)(G)-1, excluding from the investment adviser definition a family office that serves only family clients, is family-owned and family-controlled, and does not publicly hold itself out as an adviser. - [Registered Investment Adviser (RIA)](https://altss.com/glossary/registered-investment-advisor) A registered investment adviser (RIA) is a firm registered as an investment adviser with the Securities and Exchange Commission (SEC) or a US state; the status covers private fund managers as well as wealth-management firms. ### Structures and investing 4 concepts - [Holding Company](https://altss.com/glossary/holding-company) - [Direct Investment](https://altss.com/glossary/direct-investment) - [Co-Investment](https://altss.com/glossary/co-investment) A co-investment is a minority equity investment made directly in a specific portfolio company alongside a private fund sponsor's main fund, typically offered to the fund's LPs or other partners on reduced or no management fee and carried interest. - [Investment Committee](https://altss.com/glossary/investment-committee) ## Methodologies and frameworks - Standard · Version 1.2.0 ### [Altss Family Office Classification Standard](https://altss.com/knowledge-center/frameworks/family-office-classification-standard) How Altss classifies family offices: the SEC family office rule as a US regulatory exclusion rather than a general definition, accredited-investor family office categories, Altss-defined labels for single-, multi-, embedded and virtual family offices, adjacent types excluded, and the evidence each label requires. ## Canonical URL https://altss.com/taxonomy/family-offices