Picture the last stretch of a confidential CEO search for a PE-backed industrial company with about $150 million in revenue. The board hired a well-known retained firm. The slate arrives in week six: three capable people, cleanly presented. Then a director asks the question everyone in the room was thinking. Where is the operator who ran the turnaround at our largest competitor? Half the industry knows her name. The partner pauses and explains that her employer is a client of the firm. Nobody on the search team is allowed to call her.
Nothing improper happened in that room. The firm followed an off-limits agreement, which is standard practice in retained search. The problem is timing. The board learned about the constraint after six weeks and a retainer, when it could have learned about it before signing.
What an off-limits agreement is
A search firm earns its fees from companies that hire it. Those same companies do not want the firm recruiting their own executives away. So firms agree, formally or informally, not to approach a client's people for a period of time. Korn Ferry describes the practice plainly in its annual report for the fiscal year ended April 30, 2026: "Either by agreement with clients, or for client relations or marketing purposes, we are required to or elect to refrain from, for a specified period of time, recruiting candidates from a client."
Heidrick & Struggles says the same thing in its annual report for 2024: "Clients frequently require us to refrain from recruiting certain of their employees." It is a reasonable rule. You would expect the same protection if you hired the firm. It also means every client a firm signs is a company it may not recruit from.
Executive search clients Korn Ferry says it partnered with in fiscal 2026, across more than 6,500 new engagements. Each is a company the firm may be restricted from recruiting out of.
Korn Ferry, Form 10-K for the fiscal year ended April 30, 2026The decision that number points to: before you choose a firm, find out how much of your candidate market it can actually reach. The bigger the client list, the bigger that question becomes.
The admission sits in the risk factors
Public search firms list off-limits rules as a risk to their own business, which is a good sign of how much the rules bite. Korn Ferry's filing carries a risk factor titled "We are limited in our ability to recruit candidates from certain of our clients due to off-limit agreements," and adds that these agreements "can cause us to lose search opportunities to our competition." Heidrick's filing goes further: "Executive search firms that have a smaller client base than we do may be subject to fewer off-limits arrangements."
That last sentence is the largest firms explaining, in a securities filing, why a smaller firm can sometimes run a search they cannot. For the firm it is a lost engagement. For the company that already signed, it is a slate drawn from the market minus the firm's client list.
The slate you see is the market minus your search firm's client list. Ask for the list before you sign.
A worked illustration
The figures below are hypothetical, chosen to show the mechanics. They are not data about any firm.
Say your board maps 40 companies where the right CEO for a $150 million industrial business could plausibly be working today: direct competitors, adjacent manufacturers, two or three PE portfolio companies in the same niche. Now say 10 of those 40 are current or recent clients of the firm you are about to hire. A quarter of your map is closed before kickoff.
The loss may not be spread evenly either. If the blocked ten include the larger, better-run names in your sector, which is where many boards expect the strongest operators to be, the blocked quarter could hold more than a quarter of the people you most want. You will not see that in the slate, because nobody presents a candidate they could not call.
The useful part of this arithmetic is that it is knowable in advance. Your target list exists before the engagement letter does. Very few boards put the two side by side.
Why it matters more when the search is confidential
In an open search you can soften the problem. You post the role, take inbound interest, or ask a second firm to cover the companies the first one cannot touch. In a confidential search, most of those routes are closed. Two firms calling around the same market for the same unnamed seat is one of the fastest ways for a search to leak, which we covered in The Confidential Search: Five Places a Search Leaks. Exclusivity is the right structure for confidentiality. It also means one firm's blocks become your blocks.
Scope matters too. Korn Ferry's filing lists "the duration and scope of the off-limit agreement, including whether it covers all operations" among the variables. A block can cover one division or an entire company, and it can last for a defined period after the engagement ends. In a confidential search those details decide whether the most obvious candidate is reachable at all.
The candidates themselves are usually employed, often happily. That is why a confidential search verifies them carefully and late, a sequence we laid out in The Reference You Can't Call. An off-limits rule removes some of them before that sequence starts.
Seven questions to ask before you sign a retained search
- Which companies on our target map are off-limits to you, and until when? Send the firm your list of target companies and ask for a written answer against it, not a general policy statement.
- Is each block the whole company or one business unit? A block on one division of a conglomerate is very different from a block on the parent.
- Which blocks are contractual, and which are courtesy? Korn Ferry's wording separates restrictions "by agreement with clients" from those kept "for client relations or marketing purposes." The second kind is a choice the firm makes, and you should know about it.
- If our strongest candidate is blocked, will you tell us? The right answer is yes, with a name, so the board can decide whether to approach that person another way.
- How many searches is the lead partner running right now? Depth beats volume in a senior search. We showed what volume costs in The 100-Req Math.
- Who on the team has worked a seat like this in the last two years? An operator's judgment of a candidate differs from a process reviewer's, the theme of The Operator's Eye.
- How is the fee staged, and what do we receive at each stage? A retained search is usually paid as a retainer up front, sometimes a midpoint installment, and the balance when the hire is made. Each payment should line up with a deliverable you can see. How that billing works, and how it differs from calendar billing, is in the confidential search piece.
A good answer is easy to recognize. It is a marked-up copy of your own target list, returned within a few days, with each company labelled reachable, blocked until a stated date, or blocked for one unit only. A vague answer, such as "we manage conflicts case by case," tells you something too. If a firm cannot say which of your 40 companies it can call before you pay the retainer, it will not be easier to get that answer after.
Where a smaller firm fits, and where it does not
Heidrick's sentence about smaller client bases is one reason boutique retained firms win searches the largest firms cannot run. Fewer clients means fewer blocks. A boutique also has limits: a thinner research team, fewer offices, less reach across continents. If your target map is global and spans hundreds of companies, a large firm's bench may matter more than its blocks. If your map is 40 companies in one niche, the blocks may matter more than anything else.
The same standard applies to us. Ask ETHOSLINK for our off-limits position against your target list, in writing, before you sign. We run fewer searches on purpose, and we would rather tell you up front that the seat needs a fractional executive for six months, or no hire at all, than run a search with a quarter of the market missing.
When this matters less
Off-limits rules matter most when the candidate pool is small and concentrated: a CEO or CFO in a specialized industry, a technical leader with rare domain knowledge, a seat where the board already knows the five names it wants. For mid-level roles with deep, active candidate pools, the constraint rarely changes the outcome, and a contingency search can be the honest recommendation. We set out that trade-off in Retained vs. Contingency Search.
The process rule is short. Write the target map before you choose the firm. Put it in front of every firm you interview. Choose the one whose answer you can check.