Co-investment programs for single family offices

The economic logic behind co-investments

The appeal of co-investments to single family offices is straightforward: direct participation alongside a general partner in a specific deal, typically on a no-management-fee, no-carry basis. On a traditional private equity fund charging 2% management fee and 20% carried interest, shifting even 30% of deployed capital into co-investments can reduce the blended fee load materially. A family with $50M of private equity exposure paying standard terms on the full amount might face a total expense ratio — fees plus carried interest on a 2x gross return — equivalent to roughly 6–8% of invested capital over a ten-year fund life. Redirecting $15M of that exposure into fee-free co-investments compresses that blended cost meaningfully, a consideration that resonates particularly in the current environment, where net-of-fee return expectations for buyout funds have moderated toward the 12–15% range according to Cambridge Associates' 2023 benchmarking data.

But the zero-fee framing obscures real costs. Legal counsel for each co-investment transaction — negotiating side letters, reviewing co-investment agreements, structuring the holding entity — typically runs $15,000–$40,000 per deal depending on complexity and jurisdiction. Monitoring, travel to management presentations, and internal staff time add further expense. For a family writing $2–3M co-investment checks, these ancillary costs can represent 80–100 basis points of the invested amount, partially offsetting the fee saving. The families that extract genuine economic benefit from co-investment programs tend to write tickets of $5M or larger, where fixed transaction costs fall below 40 basis points and the fee arbitrage becomes genuinely significant.

GP relationship economics: what access actually costs

Access to co-investments is not a contractual right; it is a relational privilege. Most co-investment provisions in limited partnership agreements use permissive rather than mandatory language — the GP 'may' offer co-investment opportunities to certain LPs rather than 'shall.' Understanding why GPs extend co-investment access requires understanding their economics and incentives.

A GP offering co-investment does so for one of three reasons: to reduce concentration risk by bringing in additional capital on a large deal without breaching fund diversification guidelines, to accommodate a deal that exceeds the fund's remaining available capital, or to reward strategically important LPs whose backing adds reputational or relationship value. For single family offices, the third pathway is the relevant one, and it requires deliberate cultivation. A family committing $15M to a $3B buyout fund represents 0.5% of the fund's LP base — an economically inconsequential position unless accompanied by specific attributes the GP values: speed of decision-making, discretion, long-term orientation, operational expertise in a target sector, or the potential for a larger future commitment.

Co-investment access flows to LPs who solve problems for GPs, not merely to those who write large fund checks. A $15M commitment from a family with sector expertise and a 72-hour decision process is worth more to most managers than a $50M commitment from a slow-moving institution.

Practically, families should enter each new GP relationship with an explicit conversation about co-investment expectations before signing a subscription agreement. Negotiating a right of first offer on co-investments above a minimum threshold — say, $3M — is achievable for families with $10M+ fund commitments to established mid-market managers. Families committing to emerging managers at first close, where their capital is more catalytic, frequently achieve stronger preferential terms, including genuine right-of-first-offer language rather than best-efforts provisions.

Ticket sizing and portfolio construction discipline

Ticket sizing for co-investments requires a different mental framework than fund commitment sizing. Fund commitments are drawn over three to five years with capital calls that smooth concentration risk. A co-investment is a single-company, single-transaction bet with no such diversification mechanism. A family allocating 15% of its alternatives portfolio — say $12M of an $80M alternatives book — to a single co-investment has concentrated exposure that most institutional portfolio construction frameworks would flag as excessive for a single name.

The practical approach most experienced single family offices adopt is to size co-investments at 1–3% of total investable assets per transaction, with an aggregate co-investment portfolio constituting no more than 15–20% of the alternatives allocation. This allows meaningful participation — checks large enough to matter economically — while preserving diversification. For a family with $200M of investable assets and a 30% alternatives allocation ($60M), this implies individual co-investment tickets of $2–6M and an aggregate co-investment book of $9–12M across six to ten positions built over three to five years.

Geography and sector concentration deserve equal attention. Families often receive co-investment flow from their existing GP relationships, which by definition reflects the sectors and geographies those GPs favor. A family with three buyout fund relationships all focused on North American healthcare will receive healthcare co-investment flow predominantly — creating sector concentration that may not align with the family's broader portfolio construction goals. Deliberate GP selection with co-investment portfolio construction in mind, rather than as an afterthought, is a hallmark of the more sophisticated single family office programs.

Deal-by-deal decisioning: the operational bottleneck

The single most common reason single family offices miss co-investment opportunities is not deal access — it is decision-making speed. In conversations with placement agents and GP investor relations teams, the consistent feedback is that family offices receive co-investment offers but fail to respond within the window available. The typical timeline from initial co-investment offer to GP commitment deadline is five to ten business days for larger transactions, compressing to 72–96 hours for time-sensitive deals or smaller bolt-on acquisitions where the GP requires rapid LP confirmation to close.

Institutional investors with investment committees that meet monthly are structurally incapable of participating in fast-moving co-investments. Single family offices have a genuine structural advantage here — decisions can in principle be made by a principal in hours rather than weeks — but only if governance structures are designed to exploit that advantage. The families that build effective co-investment programs typically establish a pre-approved co-investment framework: a defined investment criteria document, pre-approved due diligence checklist, a pre-designated external legal counsel on retainer, and clear principal authority to commit within defined parameters (e.g., up to $5M in sectors the family knows well, pending post-commitment reporting to any advisory board).

Managing adverse selection risk

Adverse selection in co-investments is a well-documented phenomenon in academic and practitioner literature. The concern is that GPs offer co-investment in deals where they are less confident — needing external capital to close — rather than in their highest-conviction positions where they would prefer to maximize fund exposure. A 2019 analysis by Preqin examining 1,200 co-investment transactions found that co-investments generated median gross returns approximately 100–150 basis points lower than the flagship fund's overall IRR on a matched-vintage basis, though the distribution was wide and top-quartile managers showed no such discount.

The practical implication is not to avoid co-investments but to apply independent judgment rather than relying exclusively on GP conviction. A family office accepting a co-investment should conduct its own commercial and financial due diligence proportionate to the ticket size — not simply ratify the GP's investment thesis. This means engaging sector advisors for material transactions, reviewing the data room independently, and forming a view on valuation that is not anchored solely to the GP's acquisition multiple. Families that treat co-investments as passive fund extensions rather than direct investments tend to accumulate adverse selection risk over time.

Operational and regulatory infrastructure

The operational burden of running a co-investment program is consistently underestimated by families entering the space for the first time. Unlike a fund commitment — which generates one set of subscription documents, one K-1 or equivalent tax document annually, and periodic capital call and distribution notices — each co-investment is a discrete legal entity with its own subscription documents, shareholder agreements, information rights, and exit mechanics.

Entity structuring for co-investments requires advance planning. Many GPs structure co-investment vehicles as Delaware limited partnerships or Cayman Islands exempted limited partnerships, and the family office LP entity must be compatible with those structures for FATCA and Common Reporting Standard purposes. A family office investing through a complex trust structure or a multi-jurisdictional holding company needs to confirm FATCA classification and W-8 series or CRS self-certification documentation is current before participating — a process that can take two to four weeks if initiated from scratch when a deal arrives.

European families face additional considerations under AIFMD. Where a co-investment vehicle is structured as an Alternative Investment Fund and the GP acts as the Alternative Investment Fund Manager, marketing and participation restrictions under AIFMD apply, including the distinction between professional investors and retail classifications under MiFID II. Families investing through structures in EU member states should obtain a written legal opinion on AIFMD applicability before committing to co-investment programs managed by non-EU GPs.

BEPS Pillar Two — the OECD's global minimum tax framework establishing a 15% effective tax rate for large multinational groups, now enacted in over 35 jurisdictions — creates a new layer of structural analysis for co-investments held in traditionally low-tax vehicles. While most single family offices fall below the €750M consolidated revenue threshold that triggers Pillar Two's Income Inclusion Rule directly, the underlying portfolio companies in which they co-invest may be within scope, and the tax treatment of co-investment returns flowing through certain offshore vehicles may be affected by Qualified Domestic Minimum Top-Up Tax rules in the company's home jurisdiction. Families structuring new co-investment vehicles should commission Pillar Two impact analysis as part of standard pre-transaction tax review.

Building a sustainable program over time

The families that sustain effective co-investment programs share several common characteristics beyond capital. They treat GP relationships as long-term partnerships and invest proportionate time in those relationships — attending annual meetings, providing portfolio company introductions where relevant, and maintaining communication between fund cycles rather than only appearing at re-up time. They staff accordingly: a co-investment program of any meaningful scale requires at least one dedicated investment professional with private equity analytical skills and the time to respond to opportunities rapidly. Attempting to run a co-investment program as a secondary responsibility alongside broader portfolio management consistently produces suboptimal results.

They also maintain transparency internally about the program's true costs and outputs. Tracking co-investment performance on a deal-by-deal basis — including all-in costs, not just GP-reported returns — against the counterfactual of additional fund exposure is the only honest way to assess whether the program is generating net value. A co-investment portfolio generating 14% net IRR sounds attractive until compared against the fund's 16% net IRR after accounting for the family's internal management time and transaction costs. That comparison should be made annually, and the program's scale and scope adjusted accordingly.

The measure of a co-investment program is not gross deal count or notional fee savings — it is net-of-all-costs return relative to simply increasing fund commitments to the same managers. Families that make this comparison rigorously often find the optimal co-investment allocation is more selective, and smaller, than initially assumed.

For families in the early stages of building a program, the most actionable posture is deliberate patience. Committing to three to five high-conviction GP relationships over the next 24 months, negotiating co-investment provisions explicitly at the outset, building the operational and legal infrastructure before the first deal arrives, and establishing a written decision framework with pre-approved authority — these steps create the conditions for successful co-investment participation. Chasing deal flow without that foundation produces exactly the kind of reactive, under-diligenced commitments that validate the adverse selection concern rather than mitigate it.