Three labels, no regulator enforcing the distinction, and firms that describe themselves generously. What separates them is the size of transaction they work on and the kind of process they run.
Start a private conversation with the Acquisition Concierge, already scoped to brokers, advisors & banks. Pick a starting point, or describe your situation directly.
Owners routinely struggle to tell these categories apart, and the confusion is not their fault: the titles are self-applied, the descriptions overlap, and nearly every firm claims to serve the full range. The useful distinctions are practical. Who does the firm normally represent, and are they representing you or the other side? What size of transaction do they actually close, as opposed to the size they are willing to discuss? Do they run a managed process with a curated counterparty list, or work from listings? And how are they paid, because fee structure predicts behavior more reliably than anything a firm says about itself.
Generalisations with real exceptions. Use them as a starting frame, then verify against the specific firm's actual closed transactions.
Smaller owner-operated companies, frequently listed, usually seller-side. Valuable for accessing the listed population; less suited to a confidential managed process.
Lower middle market. Managed, confidential processes with curated counterparty lists. The category most private-company transactions run through.
Larger transactions, formal materials, institutional buyers and competitive auctions. Frequently more firm than a mid-market deal needs.
Retained by the buyer to run proprietary outreach against a defined thesis. Paid for effort and access rather than for a listing.
Which side the firm represents in your transaction, and whether their duty and their fee point the same way you do.
Retainers, milestone fees and success fees, and what each incentivises when a deal starts to wobble.
How to evaluate a specific firm rather than a category.
The wrong intermediary rarely announces itself. It shows up as months of poorly fitting opportunities and a fee structure that resists an exit.
A buyer without a written thesis usually gets volume rather than fit, and pays to evaluate companies that were never candidates. Several weeks of strategy work before engaging anyone routinely saves more than it costs.
Structures vary widely and there is no standard, which is itself worth knowing when a firm presents its terms as conventional. Retained buy-side searches commonly combine a monthly or quarterly retainer with a fee on closing. The questions that matter more than the headline number: what the retainer buys in defined activity, whether it credits against the closing fee, what the term is and how you exit, and precisely what event triggers the closing fee. Get all of it in writing, and have your own counsel read the engagement letter, not the firm's.
You should be extremely reluctant, whatever is permitted. Once negotiation begins, buyer and seller interests diverge sharply on price, structure, indemnity and every material term, and an intermediary compensated on closing has an interest in a deal happening rather than in either party's best outcome. If a firm proposes it, ask who they owe a duty to, how they will handle price negotiation, and get the answer in writing. Cleanest is separate representation, and the Institute's own position is that it will not advise both sides of the same transaction.
Ask for their last ten closed transactions with enterprise values and sectors, and call two or three references from that list. Firms that primarily work above or below your range will still take the engagement, and the mismatch shows up as a buyer list drawn from the wrong population, materials pitched at the wrong audience, or process discipline your counterparties find heavy-handed. Public league tables and deal databases can corroborate, but references from actual clients are more informative than any listing.
That a seller has decided to sell and has agreed to a marketed process, which is genuinely useful information and the reason listings are worth watching. It does not tell you the financials have been examined, that the asking multiple bears any relation to value, or that the recast earnings will survive a quality-of-earnings review. Listing materials are marketing documents prepared for the seller. Treat them as the beginning of diligence rather than as any part of it.
Describe your thesis and where you are. The Concierge will orient you on which intermediaries fit, including when the answer is none yet.