In Special Forces, we called it target selection. Before the mission brief, before the rehearsal, before a single asset moved — someone had to define what we were looking for and what we'd pass on. That criteria set saved lives. Getting it right before the first call saved months of search time and the capital that came with it.
Search fund operators call the same thing a buy box.
Most searchers spend the first year of their search learning this lesson the hard way. They talk to every business owner who returns an email. They dig into deals that could never clear a basic filter. They burn six months and real money before they understand: the criteria aren't a constraint. They're the mission.
This is what the data says those criteria should be.
Why the buy box matters before the first call
The Stanford Graduate School of Business tracks search fund performance going back to 1984. Their 2024 study covers 681 search funds. The average search takes 19 months and 3.2 signed LOIs before a deal closes.
That's 19 months of your life and capital. Most of the time wasted in that window is spent on businesses that never should have gotten a second look. A searcher without a clear buy box is a Green Beret who took the mission without reading the target package.
The criteria below reflect what the best operators in the ETA space actually acquire — not theory, not wishful thinking. Median acquired company data from the 2024 Stanford study.
Criterion 1: EBITDA floor — $1M minimum, targeting $2M to $4M
The median EBITDA of a business acquired by a search fund is $2.2 million.
That number matters for three reasons. First, below $1M EBITDA, you typically can't support SBA debt service plus a market-rate management salary plus basic overhead. The math doesn't work. Second, above $5M EBITDA, you're competing with institutional PE — and you're competing without their balance sheet. Third, the $2M-$4M range is where off-market deal flow concentrates. Business brokers work it. Searchers work it. Seller-financed deals happen here.
Know the floor. Build the pipeline around it.
Criterion 2: Margin quality — 15% minimum, 20%+ target
EBITDA margin is a signal, not just a metric. The median acquired business in the Stanford 2024 data carries a 27% EBITDA margin. That's not an accident.
High-margin businesses fund their own debt service and generate working capital for growth. Low-margin businesses leave no room for error. In a first acquisition, you will make operational mistakes. Margin is what absorbs them.
Below 15% EBITDA margin: pass unless there's a documented, structural reason the margin is recoverable. "Management could cut costs" is not a documented reason. It's a hope.
Criterion 3: Revenue quality — 60% recurring or contractual
Not all revenue is equal. Project revenue disappears when you stop selling. Recurring revenue compounds.
What you're looking for: - Long-term service contracts - Subscription or retainer-based billing - Regulatory or compliance-driven recurring spend (hard to cancel) - Embedded software or workflow integrations (high switching cost)
Sixty percent recurring is the working floor. Above 80% and you have something worth protecting at premium valuation. Below 40% and you're buying a sales organization, not a business.
Ask for a three-year revenue cohort analysis before the LOI. If the seller can't produce it, that tells you something.
Criterion 4: Customer concentration — no single logo above 15%
Customer concentration is the most frequently underestimated risk in small business acquisitions.
The standard: no single customer above 15% of revenue. Above 20% triggers special retention conditions in deal structure — earnouts, escrows, or consent-to-close provisions tied to contract renewals. Above 30%, expect most sophisticated search fund investors to walk.
The risk isn't just revenue. It's leverage. A customer who represents 25% of your revenue knows it. They will renegotiate. They will demand pricing concessions. They will test whether you're operationally dependent on them post-close.
Analyze concentration by logo, by geography, by sales rep, and by product. A business with no single customer above 15% by logo might have 60% of revenue in one region or one sales rep relationship. Both are concentration problems.
Criterion 5: Growth trajectory — positive, documented, recent
The median acquired search fund business was growing EBITDA at 25% at the time of purchase.
That's not a coincidence. It's a selection criterion baked into the data. Growing businesses attract searchers; declining businesses attract discounters.
What you're measuring: three years of monthly EBITDA. You want trend, not snapshot. A business that earned $2.4M EBITDA last year but earned $3.1M the year before is a different business than one that earned $1.8M three years ago and $2.4M last year. Both show $2.4M EBITDA on the broker's teaser. Only one of them should clear your filter.
Seasonality is normal. Decline is not. Know the difference.
Criterion 6: Capital intensity — low CapEx preferred
Search fund acquisitions run lean. The typical deal structure involves significant debt. That debt needs to be serviced. Every dollar of maintenance CapEx is a dollar that doesn't service debt.
Low capital-intensity businesses include professional services, software, healthcare services, specialty distribution, and business-to-business recurring services. These businesses grow on organic cash flow. They don't require equipment replacement cycles that compete with your debt coverage ratio.
High CapEx businesses — manufacturing, fleet-dependent logistics, heavy-equipment services — require a different financial structure and a different operator skill set. Some searchers specialize there. Most don't. Know which one you are before you spend due diligence dollars.
The four industries that account for most search fund acquisitions by volume: healthcare services (25%), business services (25%), software and technology (22%), and tech-enabled services (16%). All four are low-to-moderate CapEx categories.
Criterion 7: Owner exit readiness — genuine, not testing the market
This is the most overlooked criterion. It's also where deals die most often.
A seller who is "thinking about it" or "testing the market" or "seeing what offers look like" is not a seller. They are someone who is emotionally unready to let go of something they built. That emotional state does not resolve during due diligence. It escalates.
What genuine exit readiness looks like: - The owner has a stated plan for post-close (retirement, health, family) - The business has existed for 10+ years and the owner is 55 or older - There is a documented management team capable of operating without the owner's daily involvement - The owner has had prior conversations with advisors, attorneys, or a CPA about the transaction
What it doesn't look like: owners who inserted themselves back into operations after a health scare, owners with no defined post-close plan, and owners who are selling "because a friend sold."
The seller's emotional state is a proxy for transaction quality. Evaluate it early.
The fast disqualifiers
Seven criteria take time to evaluate. Some things disqualify fast:
Customer concentration above 30%. No structural patch fixes this in a first acquisition.
EBITDA below $1M. The math on debt service and management compensation doesn't work.
Declining revenue for 24+ months. Not a turnaround. A distressed asset. Different skill set, different price, different deal structure — or pass.
Non-transferable licenses. In regulated industries, change-of-control provisions in key licenses are pre-LOI deal-killers. Verify transferability before you get emotionally invested.
Owner who won't step back. Transition agreements require genuine owner willingness to hand over the controls. Without it, you're not buying a business. You're buying a job that someone else runs.
Run these checks before spending due diligence capital. Most brokers will let you ask. Most sellers will answer directly if you ask directly.
What the buy box is not
The buy box is not a guarantee. It's a filter.
A business that clears all seven criteria can still fail post-acquisition. Cultural mismatch between operator and team has been cited as the factor behind 60% to 70% of underperforming search fund acquisitions. The buy box gets you to the right starting line. It doesn't run the race.
The criteria don't guarantee you find a perfect business. Perfect businesses don't exist in the lower middle market. The criteria tell you when you've found a good enough business — one with real cash flow, predictable revenue, manageable risk, and a seller who is ready to move.
That's the mission. Know the target profile. Hold the filter. Don't negotiate the criteria because you're tired of searching.
The discipline behind the filter
Green Berets don't take every target that appears on the map. They take targets that meet the mission criteria. The ones that don't meet criteria get passed to another team, filed for a different day, or simply declined.
Search fund operators who apply the same discipline close better deals. They close them faster. They don't spend $40,000 in due diligence on a business with a customer concentration problem they identified in week two.
The buy box is not a limitation. It's the op order for the acquisition phase of your career.
Run the filter. Protect the process. The right target is out there.
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*Next: once you've identified a target that clears your buy box, the diligence process begins. [What most search fund buyers miss in due diligence →](/blog/search-fund-due-diligence/)*
*Source: Stanford Graduate School of Business [2024 Search Fund Study](https://www.gsb.stanford.edu/faculty-research/case-studies/2024-search-fund-study)*
