By Kevin Luu, Co-Founder and Chief Learning Officer. Reviewed on 2026-09-30.
A dedicated single family office gives one family its own staff for investments, tax, estate coordination and governance, but it typically only makes economic sense for families with very large fortunes, far beyond what most high-income W-2 families hold. A traditional wealth manager is far cheaper and mainly runs a portfolio. For a high-income W-2 family with young children, the practical middle ground is a multi-family office: shared staff, family office scope, and a fee closer to a wealth manager’s.
The real difference is not the investment menu. It is who owns the whole picture: RSU tax, estate documents, guardianship, giving, and the record of how the parents make decisions that the kids will one day need. This guide compares the three models on cost, scope and governance, with a worked example for a $1.4 million California household.
What a “family office” legally is, and why the label is loose
Under the SEC’s family office rule, a true single family office advises only one family (plus certain key employees), is wholly owned and controlled by that family, and does not hold itself out to the public as an investment adviser. An office that meets those conditions is not treated as an investment adviser under the Investment Advisers Act at all, so it does not register with the SEC (17 CFR 275.202(a)(11)(G)-1).
Everything else that calls itself a family office, including multi-family offices, serves many families and so is generally a registered investment adviser like any wealth manager. “Family office” is a description of scope, not a license. That means you check a multi-family office the same way you would check any adviser: its Form ADV on the SEC’s Investment Adviser Public Disclosure site, how it is paid, and whether it acts as a fiduciary on every account. Our guide to vetting a financial advisor walks through those checks.
Family office vs. wealth manager: what each one actually covers
| Area | Single family office | Multi-family office | Traditional wealth manager |
|---|---|---|---|
| Who it serves | One family only | A limited number of families | Many households |
| Typical pricing | Family pays the full cost of staff, systems and office | Flat or retainer fee, sometimes plus a percentage of assets | Usually a percentage of assets managed |
| Investments | Yes, often including private deals | Yes | Yes, the core service |
| Tax planning (RSUs, ISOs, AMT, state moves) | Yes, in-house | Usually yes | Varies; often left to the CPA |
| Estate and guardianship coordination | Yes | Usually yes, working with your attorney | Often a referral only |
| Employer accounts held elsewhere (401(k), stock plan, ESPP) | Included | Usually included in planning | Often not reviewed if not managed |
| Family governance and educating the kids | Formal, if the family wants it | Varies widely; ask for specifics | Rare |
The row that matters most for a W-2 family is the employer-account row. Much of a tech or biotech family’s wealth sits in an RSU brokerage account, a 401(k) and an ESPP that a percentage-of-assets manager does not run and may not plan around. See what held-away assets are for why that gap is expensive.
Why a single family office rarely fits a $750k to $3M household
A single family office is a small company the family owns. It needs people: someone to run investments, someone to handle accounting and tax, often someone for administration and compliance. The family pays all of it, whether markets are up or down.
For a family with a $1.4 million household income and $3.5 million invested, even a lean two-person office would likely cost more each year than any outside adviser, and it would still need outside estate attorneys and CPAs. The model works when the costs are spread over a very large balance sheet. At this income level, the family gets most of the same coverage by sharing staff with other families.
Worked example: a $1.4M California household compares three proposals
Assumptions (illustrative): married filing jointly in San Mateo County. One spouse is a physician, the other works at a biotech company. W-2 income is $1.4 million, of which $400,000 is RSU income at vest. Investable assets are $3.5 million, of which $1.2 million is employer stock. Two children, ages 4 and 8. Fees below are hypothetical and chosen to show the math, not market averages.
- Traditional wealth manager at 1.0% of assets it manages. It will manage $2.3 million (the employer stock stays at the stock plan broker). Fee: $23,000 a year. Tax return, estate documents and RSU planning are not included.
- Multi-family office at a flat $30,000 a year. Covers the full $3.5 million, including the employer stock, plus tax planning, estate coordination with the family’s attorney, and insurance and benefits review.
- Single family office. Two staff at a hypothetical $500,000 combined cost, about 14% of the family’s investable assets each year. Not a real option at this size.
Option 1 looks cheapest. But consider one recurring issue it leaves untouched. For 2026, the federal 37% bracket for joint filers starts at $768,700 of taxable income, and this family is well above it. Assume the employer withholds the optional flat 22% federal rate on the $400,000 of RSU income (supplemental wages under $1 million) (IRS Publication 15). The 15-point gap is about $60,000 of federal tax not withheld on those RSUs alone, before California tax. On top of that, California SDI takes 1.3% of all wages for 2026 with no cap (EDD), and California taxes any gain when those shares are later sold as ordinary income, with no lower rate for long-term gains (FTB).
Someone has to plan estimated payments, decide how much of the $1.2 million in employer stock to sell and when, and coordinate that with the CPA. If no one owns that job, the family can end up paying for it in underpayment penalties, a surprise April bill, or a concentrated position that stays concentrated. That ownership is what the extra $7,000 in option 2 buys. Whether it is worth it depends on how much of the family’s time is currently going into these decisions, and how often they get made at all.
Legacy planning: where the models differ most
For 2026, the federal estate and gift tax basic exclusion is $15,000,000 per person, made permanent by the 2025 tax law and indexed from 2027 (IRS). Older articles that warn of a 2026 drop to about $7 million are out of date. Most families at this income level are unlikely to owe federal estate tax.
Washington is different. Its estate tax exclusion is $3,000,000 for deaths from July 1 to December 31, 2026 (WA DOR). A Bellevue couple with a paid-down house, retirement accounts, Amazon or Microsoft stock and life insurance can cross that line long before they feel wealthy. California does not currently collect an estate tax (no California estate tax return is required for deaths on or after January 1, 2005, per the State Controller), but California families still need guardianship choices, a revocable trust to keep assets out of probate, and decisions about when children receive money.
A wealth manager may refer you to an attorney. A family office, single or multi, is expected to keep those documents current, check beneficiary designations against the trust, and make sure the plan matches what the parents actually want. Ask any provider who updates the plan after a new child, a move between California and Washington, or a large vest.
Family governance: the part most families skip
Governance sounds like something for families with a board and a foundation. For a family with kids under 12, it is simpler: written answers to questions the children will one day ask. Why did you buy this house and not a bigger one? How did you decide what to give to charity? What do you expect us to do with an inheritance?
As Kevin Luu puts it: “Your kids will inherit your money. Will they inherit your judgment?” Traditional wealth managers rarely touch this. Some family offices offer it as a formal service. When you compare proposals, ask to see what the governance work actually produces: a family mission statement nobody reads, or a record of real decisions the kids can learn from.
Common mistakes when choosing between the models
- Comparing only the fee. A lower percentage fee on part of your assets can leave the costliest decisions, like RSU taxes and concentration, unplanned.
- Trusting the “family office” label. It is not a regulated title. Check Form ADV, the fee schedule and the fiduciary commitment.
- Ignoring held-away accounts. If the adviser does not plan around your 401(k), stock plan and ESPP, a large share of your net worth has no one watching it.
- Waiting for a liquidity event. Estate documents, guardianship and the kids’ money habits matter now, not after the next vest cliff.
What to document for your kids
Whichever model you choose, write down why. One page is enough: what you were looking for, what you were paying, what you decided the adviser would and would not handle, and who the kids or a guardian should call if something happens to you. That page is part of your FamilyKnowledge® Library. Conversations fade. Documentation compounds.
Frequently asked questions
Is a multi-family office the same as a wealth manager?
Legally, both are usually registered investment advisers. The difference is scope and pricing. A multi-family office typically plans across tax, estate, insurance, benefits and governance for a smaller number of families, often for a flat fee. A traditional wealth manager usually focuses on managing a portfolio for a percentage of assets.
Are there family offices that specialize in tax optimization and legacy planning?
Yes. Many multi-family offices lead with tax and estate work rather than investments, which suits W-2 families whose biggest decisions are RSU and ISO taxes, state residency, and trusts for minor children. Ask for a sample plan showing how they handled equity compensation and estate documents for a family like yours.
How do I compare family office fees fairly?
Convert every proposal to annual dollars on your full balance sheet, then list what is excluded: tax preparation, estate legal fees, accounts they will not review. A flat fee that covers everything can cost less in total than a lower percentage fee plus separate bills. Our guide to what a wealth manager costs shows the common fee structures.
Next step
Before you take any meetings, list every account you own, including employer plans, and write next to each one who is responsible for it today. Gaps on that list show which model you need. If you want a second view, Bright Advisers’ Age Five Family Office™ runs a Tax & Wealth Assessment that covers tax management, estate planning and family governance for W-2 families in California and Washington.
This is general education, and the right move depends on the family’s full picture.
Kevin has advised high-income W-2 tech and biotech families since 2015, and leads the education-first Age Five Family Office from Brea, California.
Connect on LinkedIn → · About KevinThis is part of how we approach Family Governance for high-income W-2 families at Bright Advisers.
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