How to Vet a Staffing Agency: 12 Questions That Expose the Weak Ones

Last updated: August 27, 2026

By Tom Kenaley, Senior Partner and President, KORE1

Vetting a staffing agency comes down to four things a firm either can or cannot produce on request, a named recruiter, a 12-month retention rate, worker classification paperwork, and a written conversion fee schedule. Everything a sales team brings to the first meeting is optional. Those four are not, and the firms that stall on them tend to stall on them for the same reason.

A VP of engineering at a medical device manufacturer walked me through her bake-off last spring. Three agencies, one scorecard, points for industry experience and cultural fit and responsiveness. Very tidy. She showed me the spreadsheet. She picked the firm with the best deck and the warmest account executive, signed a two-year master services agreement, and got a Snowflake data engineer on site within eleven days.

Seven weeks later her own legal team found him during a routine audit. He was not the agency’s employee. He was a 1099 contractor working through a second firm the agency had quietly subcontracted, and nobody on her side had known there was a second firm. Nobody had asked.

Nothing on her scorecard would have caught it. Not one line.

Her scorecard was the problem. The standard advice on how to choose a staffing agency asks about industry experience and turnaround time and communication style, and every agency on earth answers those beautifully, because those answers cost nothing to give and nothing to fake. The twelve questions below cost something. Each one has a document, a number, or a named human behind it, which means a weak firm has to either produce the thing or visibly refuse.

I am a staffing agency telling you how to interrogate staffing agencies. I hear it. KORE1 sells the exact service this page is training you to be suspicious of, and I have personally sat on the wrong end of most of these questions, a few of them from clients who got the list from an earlier version of this article. We keep sending it out anyway. An agency that cannot survive question seven is going to cost you a quarter, and I would rather you spend that quarter somewhere other than here than spend it with us and remember it badly.

There Are About 27,000 of Us, and the Weak Ones Look Identical to the Good Ones

The American Staffing Association counted roughly 27,000 staffing and recruiting companies in the United States as of 2021, running close to 54,000 offices between them, and its 2024 figures put nearly 2.2 million temporary and contract employees at work in an average week. That is a fragmented market by any measure, and fragmentation is what makes vetting hard. There is no licensing body. There is no exam. Two people with a laptop and a job board subscription can open a firm on Monday and pitch you on Thursday with a website that looks exactly like the website of a firm that has been placing engineers since 2005. The websites match. The firms do not.

Demand is not helping. Temporary help services has added jobs every month of 2026 and posted the second-largest gain of any of the 300-plus industries the Bureau of Labor Statistics tracks, per the July reading in the Staffing Industry Analysts jobs report, with the temp penetration rate sitting at 1.58%. Something like one in ten of this year’s new jobs came out of that channel. Money pulls operators in fast. The fast ones are rarely the careful ones.

So the burden falls on you. I know. It is a genuinely unfair thing to hand a hiring manager who already has six open reqs and a headcount-freeze rumor going around, but there is no third party doing this screening on your behalf, and the cost of skipping it lands entirely in your quarter.

Questions 1 Through 4: Who Is Doing the Work

1. Name the recruiter who will work my req, and tell me what else is on their desk this week

The person selling you is almost never the person searching for you. That is normal and fine. What is not fine is finding out in week two that your req went to a shared pool, or to somebody eleven months into the industry with thirty-one other reqs open.

Ask for the name. Then ask two follow-ups that are hard to dodge. How long has that person been recruiting in this specialty, and how many active searches are they carrying right now? A senior recruiter running eight to twelve reqs is normal. Twenty-five reqs means your search is a lottery ticket. Ask the number. Our recruiters average more than fifteen years in their verticals, which is not a brag so much as the reason we can answer this question in the first meeting without checking.

2. Show me your last five placements in this stack and how long each one lasted

Fill counts are vanity. Ignore them. Anybody can fill a req if you accept the sixth-best person and stop asking questions. Retention is the number that maps to your actual outcome, and almost nobody volunteers it.

KORE1 runs 92% 12-month retention on placements. I put that number in writing because it is the one I would want if I were buying, and because a firm that has never calculated its own version of it is telling you something. Not necessarily that they are bad. Possibly just that no client has ever asked them for it. Somebody should.

3. What is your submittal-to-interview ratio on roles like mine?

One wrong answer shape exists here, and it is the answer that sounds generous.

If a firm brags about sending you twelve candidates in seventy-two hours, they have told you their model. The model is volume. Somebody ran a keyword search, pulled every resume with Kubernetes on it, and forwarded the pile. A firm doing real screening submits three to five people and expects two of them to interview. When the ratio slides past eight submittals per interview, you have hired yourself a very expensive resume-forwarding service, and the hidden cost is not the fee. The cost is the forty hours your engineering leads spend reading profiles a recruiter should have killed.

4. Who sources for you, and where do they sit?

Plenty of good firms use offshore sourcing support. The practice is fine. The problem is the firms who do it and will not say so, because the same instinct that hides a sourcing team tends to hide other things, and because you deserve to know who is representing your company’s name in a first outreach message to a candidate who has never heard of you.

Ask it flatly. A firm that answers “we have a research team in Hyderabad. Here is how their work gets reviewed before anything reaches you” has just passed. A firm that gets cagey has just failed. It took nine seconds.

Questions 5 Through 8: The Paper Nobody Reads Until It Matters

5. Are the people you place W-2 employees of yours, or 1099 contractors, or subcontracted through someone else?

That subcontracting layer is what ended the story I opened with. It is the single highest-consequence question on this list.

When a staffing firm places someone with you, federal agencies generally treat both companies as employers of that worker. The EEOC’s enforcement guidance on contingent workers, on the books since 1997, says the client can be liable for discrimination against a staffing firm’s employee where the client knew or should have known and failed to act. OSHA’s Temporary Worker Initiative is blunter still, holding that the host employer and the staffing agency are joint employers for safety purposes and that neither one can contract its way out. Their phrasing is that neither employer may avoid its responsibilities by requiring another party to perform them. Read that twice if you have ever been handed an indemnification clause and felt reassured.

Classification is moving underneath all of this too. In February 2026 the Department of Labor proposed a new independent contractor rule, one that would rescind the 2024 standard and lean instead on control and on whether the worker has any genuine shot at profit or loss of their own. The mechanics can wait. The line worth carrying into a vendor meeting is the department’s own, that actual practice outweighs contract language. What the agreement calls the worker is not the test. What happens on Tuesday is the test.

So ask for the classification, ask whether any part of the placement is subcontracted, and ask for that in writing. If the answer is layered, you want the layers named before signature, not during an audit.

6. Send me your certificate of insurance and your workers’ compensation experience modifier

Two documents. Both exist or they do not. An agency that already holds both will email them inside four minutes, and an agency that does not will need a week and a phone call with somebody’s broker.

The certificate tells you what coverage actually stands behind the people on your site. The experience modifier tells you how their claims history compares to the rest of their industry, and a modifier meaningfully above 1.0 means their workers get hurt more than average, which is a fact about their screening and their safety program rather than about bad luck. For reference, we carry professional liability at $5 million, general liability at $1 million per occurrence and $2 million aggregate, and a $5 million umbrella above it. You do not need to match those numbers to your vendor. You do need to see theirs before someone is standing in your building.

7. Walk me through the replacement guarantee, and then tell me what voids it

Every firm has a guarantee. Ask to read it. The guarantee is not the product. The exclusions are the product.

Ask whether a failed placement gets you a replacement search or a pro-rated credit, because those are wildly different things when the seat is still empty in month four. Ask how many days it runs, and whether the clock starts on the offer, the start date, or the first invoice. Then ask what voids it, which is where the interesting language lives. Layoffs and role eliminations usually void it, reasonably. Some agreements also void it if the candidate’s scope changes, and scope always changes, which is how a ninety-day guarantee quietly becomes a thirty-day guarantee without anyone lying to you.

8. Give me the conversion fee schedule in writing, tiered by hours worked

You will want to hire one of these contractors eventually. Most clients do. It is the happiest outcome in this business.

A fair schedule declines with hours worked and eventually hits zero, because the agency has already earned its margin on the hours. A schedule that stays flat at 20% no matter how long the person has been on your site is a schedule designed to punish you for a good outcome. Ours steps down in tiers and reaches zero at the low end of the range you will see in the market, a little past a full year of hours. Get the number and the tiers on paper during selection. Nobody has ever negotiated a conversion fee successfully at the moment they announced they wanted to convert someone.

Questions 9 Through 12: What Happens When It Goes Sideways

9. What is in your off-limits clause, and how long does it run?

Read this one as the reverse of everything above. It is not about their obligations to you. It is about yours to them, and about the people you already employ.

Most master services agreements include a non-solicitation provision that stops the agency from recruiting out of your company. Check the term, check whether it covers the whole company or only the divisions they have worked with, and check whether it survives the end of the relationship. I have watched a client sign a two-year MSA with a firm whose clause protected only “personnel directly placed by the agency,” which protected nobody, and then get four senior engineers poached by that same firm’s other desk fourteen months later. Legal read the contract. Legal missed six words. Nobody broke anything.

10. What do you tell candidates about us?

Ask to see the outreach message. Not a description of it. The message itself, pasted into an email.

Fall-offs in the first sixty days are usually not about skill. They are about a candidate who was sold a story that did not survive contact with the job, and by the time you find out, you have burned six weeks and some goodwill. If the pitch describes your team accurately, including the annoying parts, the agency is protecting your brand. If it reads like a recruiting brochure written by somebody who has never spoken to your hiring manager, you have your answer.

11. How do you handle a co-employment problem, and who is the human I call?

A name and a phone number. Nothing else counts here.

When a contractor files a complaint, or gets hurt, or claims unpaid overtime, the clock matters more than the policy. You want to know who at the firm owns that call, whether they are available outside business hours, and what their process is in the first twenty-four hours. Firms with real infrastructure answer instantly, because they have run the drill. Firms without it start describing a philosophy. Listen for the difference.

12. Which of my open roles would you decline to work, and why?

My favorite. If I only got one question, I would spend it here.

An agency that says yes to all six of your reqs is either enormous or lying, and you can usually tell which within a sentence. A firm with real specialization will look at your list and tell you that they are strong on the two data engineering seats, competent on the platform role, and that you should give the embedded firmware req to somebody else. That answer costs them money. It is also the single most reliable predictor I know of a relationship that lasts, because a firm willing to give up revenue in a first meeting is a firm that intends to be there for the second contract.

Watch the pause before the answer. The pause carries the honesty.

What Weak Answers Sound Like

Five of the twelve, side by side. You will hear versions of the left column more often than you would expect, and they rarely sound evasive in the room. They sound smooth.

How to Run This Without Burning Three Weeks

Twelve questions across four vendors is a lot of calendar. Sequencing cuts it down. Run the cheap disqualifiers first and most of the calendar disappears on its own.

1. Send questions 5, 6, and 8 by email before you book a single meeting. Classification, insurance, conversion schedule. All three are documents, and roughly half your list will disqualify itself here without anyone having to be diplomatic about it.
2. Give the survivors forty-five minutes each. Questions 1, 3, 10, and 12 are conversational and they reward listening for hesitation rather than grading the content of the answer.
3. Send questions 2, 7, 9, and 11 to whoever redlines your contracts, along with the draft MSA. Your legal team is faster at 7 and 9 than you are, and they will spot the scope-change exclusion in about four minutes.
4. Pick two finalists and give each of them a live req, not a hypothetical one. Same req, same week. Watch the submittals.

That last step is worth more than the other three combined, and most buyers skip it because running a parallel search feels wasteful. It is not wasteful. It is the only part of the process where you observe the actual product instead of a description of it. Compensation questions belong in this window too, and if you want the market numbers before the conversation starts, our salary benchmark assistant will give you a range to argue from.

When You Should Not Hire a Staffing Agency at All

Real answer, against my own interest. If you are hiring more than roughly six to seven technical people a year on a steady cadence, an in-house recruiter is usually cheaper than agency fees, and we have run that arithmetic in detail in our breakdown of staffing agency versus in-house recruiter costs.

If the role is genuinely generalist and your employer brand is strong, your own careers page will produce candidates. If you need one person, once, and nothing about the search is urgent, post it and wait.

Agencies earn their fee in three situations. Scarce skills, real deadlines, and searches you cannot run publicly. Outside those three, we are a convenience, and convenience is not worth 20% of a salary.

How We Answer These

Fair is fair. If I hand you a list built to make firms squirm, you should see what happens when it points back at us.

KORE1 has been placing IT, engineering, accounting and finance, healthcare IT, digital and creative, HR, biomedical, and light industrial talent since 2005, across more than thirty U.S. metros. Our average time to hire on IT roles runs 17 days, against the 39-day median time to fill that SHRM’s 2026 recruiting benchmarking report gives for non-executive roles. Retention at twelve months is 92%. Recruiters average fifteen-plus years in their specialty. Our Glassdoor rating is 4.7 across 219 reviews, which is a rating our own people gave us rather than one we bought.

Everyone we place on a contract basis is our W-2 employee. We do not subcontract a placement without telling you in writing first. The COI goes out the same day you ask. Same with the experience modifier.

The engagement models are contract staffing when the need has an end date, direct hire staffing when it does not, and project staffing when you need a small team rather than a person. If you are evaluating a larger augmentation program rather than a single seat, our enterprise IT staff augmentation practice covers how that gets governed, and the staff augmentation cost breakdown covers the rate math in more detail than fits here.

Things Buyers Ask Us at This Stage

How many agencies should I actually put through this?

Three to vet, two to test with a live req. More than four vendors on one search creates candidate collisions, where two firms submit the same person and you inherit an argument about who owns the placement.

The collision problem is worse than it sounds. Ownership disputes tend to surface after you have already made an offer, and the candidate is the one who watches it happen.

Is a 25% fee too high?

Not by itself. In our own agreements and in the ones clients bring us to compare, direct hire fees cluster between 20% and 25% of first-year base for most professional roles, and the number only becomes a real signal once you know what sits behind it.

A 25% fee from a firm with a hundred-and-twenty-day guarantee, a named senior recruiter, and a published retention number is a better buy than 18% from a firm that cannot answer question two. Cheap search is expensive twice, once when it fails and again when you restart it. Where fee percentage genuinely matters is contract work, where the markup compounds across every hour worked for as long as the person is there.

They will not tell me their markup. Red flag or normal?

Normal for the exact number, concerning for the structure. Most firms treat the bill rate as the product and will not itemize, but any legitimate agency can tell you what their markup covers.

What you want is the composition. Employer payroll taxes, unemployment insurance, workers’ compensation, general liability, benefits, and then margin. Burden alone typically runs somewhere in the high teens to low twenties as a percentage of pay rate before anyone makes a dollar. A firm that presents its entire markup as pure profit does not understand its own P&L, and a firm that refuses to name a single component is hiding the ratio.

We used one agency for six years and they got sloppy. Now what?

Run the twelve questions on them. Incumbency should be tested on the same terms as a new vendor, and the answers you get to questions 1 and 3 will usually explain the decline by themselves.

Nine times in ten it is turnover on their side. The recruiter who knew your systems left, your account rolled to someone newer, and nobody mentioned it because nobody at the agency thought of it as news. That is fixable in one conversation if you catch it. It is not fixable after two bad hires.

Do these questions work for temp and light industrial too, or just IT?

All of them apply, and questions 5, 6, and 11 matter more, not less. Safety and classification exposure rises sharply the moment your placements are on a floor, in a lab, or on a site.

The workers’ compensation experience modifier moves from useful to essential in those environments. So does asking who conducts site-specific safety training, since OSHA splits that duty, generally putting generic training on the agency and site-specific training on you.

How fast should a good agency come back with candidates?

48 to 72 hours for a first slate on a contract role, one to two weeks on a direct hire search that requires real market mapping. Faster than 24 hours usually means a bench, not a search.

A bench is not automatically bad. It is only bad when it is presented as a search, because a firm showing you three people it already had is showing you its inventory rather than your market. Ask which one it is. Honest firms will just tell you.

Where to Take This

Print the twelve. Take them into the next vendor call and watch what happens on five, seven, and twelve, because those three do most of the work.

If you would rather point them at us first, that is a reasonable use of an afternoon. You can talk to a KORE1 recruiter or call 949-706-6990, and we will answer all twelve on the first call, including the ones where the honest answer is that your req belongs somewhere else.

Vetting the firm is half of it. The other half is how you run the engagement once the contractor is in the seat.