Sub-vendor Layering in IT Staffing and Why Fewer Is Better

How sub-vendor layering works in IT staffing

Sub-vendor layering is the chain of companies that sits between the end client who needs an IT consultant and the consultant who does the work. My opinion is simple. Every layer has to earn its place, and for a prime vendor the best sub-vendor is one level away, with the consultant on its own payroll.

The catch is that most layers are invisible from the top. The end client sees its MSP. The MSP sees the prime. Nobody above the prime knows how many companies sit under it until a rate changes or the same resume shows up twice.

A typical chain looks like this. The end client is the company that needs the work done. Many large clients run contract labor through an MSP, a managed service provider that runs the program and releases requisitions through a VMS, the vendor management system where approved suppliers submit candidates and timesheets. The prime vendor is the supplier with a direct contract in that program. A sub-vendor works under the prime with its own agreement and brings candidates the prime does not have. Below that you often find a second sub-vendor, and sometimes the consultant's own corporation on a C2C contract. We explain those pay types in our guide to C2C, W2 and 1099.

Wanware works mainly as a sub-vendor to prime vendors and MSPs, so this is the seat we sit in. If you want to see how we set up that relationship, our supplier information for prime vendors page has the details.

What each of the layers in IT staffing adds

Each of the layers in IT staffing can add something real. The MSP gives the client one program, one set of rules and one invoice. The prime vendor carries the client contract, the insurance the client requires and the payment risk. A good sub-vendor adds reach, meaning candidates in a skill or a city the prime cannot cover with its own recruiters.

The trouble starts below that. A second sub-vendor usually adds nothing the first one could not do with one more phone call, but it still takes a margin, and the bill rate at the top does not grow to pay for it. So the money comes out of the consultant's pay rate. A consultant paid below the market is the one who leaves early.

The federal government has a name for this. The FAR clause on limitations on pass through charges says the government will not pay excessive pass through charges, which it defines as overhead and profit charged by a contractor or subcontractor that adds no or negligible value to work done by a subcontractor below it. The same clause makes the contractor tell the contracting officer in writing when subcontracted work grows past 70 percent of the total cost. Private staffing contracts are not bound by the FAR, but the logic carries over cleanly. If a layer only forwards a resume, it is a pass through, and somebody pays for it. That is the real cost of sub-vendor layering.

The GAO report on oversight of pass through contracts, published in December 2014, shows why Congress cared. The three agencies it reviewed spent about $322 billion on goods and services in fiscal year 2013, and lawmakers were worried that the government could overpay contractors that add little or no value to work their subcontractors perform. If federal buyers with auditors worry about this, a prime vendor with a thin margin should worry more.

Prime vendor vs sub-vendor and who the employer is

The question that matters most in any chain is who employs the consultant. It decides who runs payroll, who completes Form I-9, who carries workers' compensation and who answers the phone when something goes wrong.

US agencies answer it by looking at control. The IRS page on independent contractor or employee status says all evidence of control and independence must be weighed, grouped as behavioral control, financial control and the type of relationship. An employer withholds and deposits income tax, Social Security and Medicare from an employee's wages and pays its own share. That is one company, with one name on the consultant's Form W-2.

USCIS says in its Form I-9 exceptions guidance that in most cases workers supplied by a staffing agency are employees of that agency, and the agency completes Form I-9 for each worker it provides. So the eligibility check belongs to the company that actually hires the consultant.

Being the employer of record does not remove everyone else's duties. OSHA's page on protecting temporary workers says the staffing agency and its client, the host employer, are joint employers of temporary workers and are jointly responsible for a safe workplace. The Department of Labor's proposed joint employer rule, announced in April 2026, names staffing agencies and their clients as an example of vertical joint employment. It would ask whether a company hires or fires the worker, supervises the schedule or conditions of work to a substantial degree, sets the rate and method of pay, and keeps the employment records. It was published as a proposal, so check whether it has become final before you rely on it.

Now apply those four questions to a chain of five companies. The answers spread across so many hands that nobody can say with confidence who the employer is. A prime that cannot tell you who sets its consultant's pay rate does not really know who its consultant works for.

Why a sub-vendor one level from the prime is the better choice

Put those facts together and the case for a short chain is plain logic. When the sub-vendor is one level below the prime and the consultant is on that sub-vendor's own W2 payroll, the prime gets four things.

• A clear right to represent. The candidate signs it with the company that will employ them, for one requisition and one end client, so there is no doubt about who may submit them.
• No duplicate submissions. The resume does not travel down a chain and come back up through two doors, which is how the same consultant reaches an MSP twice.
• One accountable employer. The same company runs payroll, completes Form I-9, withholds taxes and carries the coverage the contract requires. When the prime calls, the person who answers is the employer.
• Fewer markups. The bill rate covers two margins, the prime's and the sub-vendor's, instead of three or four, so more of it can reach the consultant.

C2C is not the problem by itself. A consultant with a real corporation who contracts through one sub-vendor is still a short chain. The problem is a chain where the real employer is a company the prime has never heard of, two levels down, and nobody above it has seen a Form W-9 or an insurance certificate. Our checklist for onboarding a new sub-vendor covers what to ask for before that happens.

My advice to a prime vendor is blunt. On every submittal, ask the sub-vendor who employs the consultant and on what pay type. If the answer is a third company, ask what it adds. If nobody can say, treat it as a pass through and decline the resume. It feels slow, and it is still much faster than explaining a duplicate submission to an MSP.

Our own commitments to primes and MSPs are short. Rate and terms in writing before any resume moves. Signed right to represent, no duplicate submissions. Never contact the end client directly. Background check before every start, at our cost. What we collect from each candidate is listed in what to collect before client submittal, and our background check and Form I-9 compliance page explains the checks.

If you are a prime vendor or MSP filling contract, contract to hire or direct hire roles, our IT staffing services page lists the roles we fill.

Written by

Israr Kazmi

Israr Kazmi is the founder of Wanware Technologies, the IT staffing, recruitment and consulting division of iCareBilling LLC, an American health tech company based in Chicago, Illinois. He writes about technology, healthcare, health tech and AI automation, with a forward-looking view of where these fields are heading. He also covers recruitment, talent placement, vendor partnerships and careers on the corporate side of technology and healthcare.

More about the author