Hiring someone in a state or country where you have no office raises a question most owners never think to ask: who is the legal employer of that person? A PEO and an EOR answer it differently, and the answer decides which one you can even use. The choice is not really about features or price. It is about legal structure, and once you see the structure the decision usually makes itself.
This guide explains the difference the way the IRS and the Department of Labor actually frame it, gives you a table and a decision tree to place your own situation, and is honest about the case most comparison articles skip: when a US company needs neither.
What a PEO is
A Professional Employer Organization (PEO) enters a co-employment relationship with your business. You keep directing the work; the PEO handles payroll, benefits administration, and HR compliance. Crucially, you keep your own legal entity: the PEO partners with your company, it does not replace it. That is why a PEO only works in states where you are already a registered business. For the mechanics, see how a PEO works and what co-employment means.
What an EOR is
An Employer of Record (EOR) is a company that legally employs a worker on your behalf. The EOR signs the employment contract, runs payroll, files taxes and provides benefits under its own legal entity and its own tax ID. You still direct the person's daily work, but the EOR carries the legal employer's obligations. Because the EOR already holds a legal entity in the location, you can hire there without registering a business of your own. That is the entire reason the EOR model exists: it stands in for an entity you do not have.
The core difference: who is the legal employer
This is the single distinction everything else follows from.
With a PEO, employment is shared. Co-employment means two organizations divide the employer's responsibilities for the same workers: you manage the work, the PEO manages payroll taxes, benefits and compliance. Both appear in the arrangement, and you must have your own registered entity where the employees work.
With an EOR, there is one employer on paper, and it is not you. The contract, the tax filings and the benefits are all in the EOR's name. You have no entity requirement because the EOR's entity does the job.
A nuance worth knowing, because it surprises people: "co-employer" is not a term in federal tax law. Under Internal Revenue Code section 3511, a certified PEO (CPEO) is treated as the employer, and no other entity is treated as the employer, of a worksite employee, but only for the wages the CPEO actually pays, and the CPEO is solely liable for the federal employment tax on those wages (IRS, third-party payer arrangements). So even in "co-employment," the tax system assigns a single employer for the money that flows through the PEO. The shared part is real at the state and contractual level; the federal tax filing is not split.
PEO vs EOR by legal structure
| Legal structure | PEO (co-employment) | EOR (employer of record) |
|---|---|---|
| Who is the legal employer | Shared: you and the PEO both hold employer roles under a co-employment contract | The EOR alone; it is the employer named on the contract |
| Federal employment-tax filing | A certified PEO files and is solely liable for federal employment tax on the wages it pays, under its own EIN (IRC section 3511) | The EOR files all payroll taxes under its own entity and EIN |
| "Co-employment" under federal tax law | Not a federal tax term; the IRS treats a CPEO as the employer for wages it remits, not as a "co-employer" | Not applicable; the EOR is the sole employer |
| Do you need your own legal entity where the worker is | Yes: you must be a registered business in that state | No: the EOR's entity stands in for yours |
| State registration | PEOs register or are licensed at the state level; you keep your own state registrations too | The EOR holds the local entity and registrations; you hold none for that worker |
| Wage-and-hour liability | Shared: joint employers are jointly and severally liable for wages (DOL, FLSA) | Primarily the EOR, as the legal employer |
| Where it works | Within the US, in states where you are registered | US states or foreign countries where you have no entity |
Structure sourced to IRS third-party payer / CPEO guidance (IRC section 3511), the U.S. Department of Labor's joint-employment guidance under the FLSA, and NAPEO's state regulatory database. Retrieved September 25th, 2026. General mechanics; confirm specifics for your states and situation before you sign.
Which one a US company needs
Put your own situation through the same two questions the structure forces: where are the workers, and do you have an entity there? For a US company of 5 to 500 employees with one or two foreign hires, the path usually resolves cleanly.
Read it top to bottom. A PEO is the answer whenever you have (or will register) an entity where the worker is and want more than bare payroll. An EOR is the answer only when you have no entity where the worker sits and will not create one, which is almost always a foreign hire or a one-off in a state you do not want to register in.
When a US company needs neither
An honest comparison has to include the case where the answer is neither.
- If everyone you employ works in a state where your business is already registered, and your only real need is running payroll, a payroll service handles pay and tax filing without co-employment or a new legal employer.
- If you are hiring a single worker in a state where registering your own entity is quick and inexpensive, a direct hire on your own payroll can be the simplest route of all.
- If you already have HR and benefits you are happy with and only want to offload administration, an arrangement like an ASO or HRO outsources the work without co-employment; see ASO vs HRO vs PEO.
The rule of thumb: a PEO earns its fee when benefits access, multi-state compliance and HR load are worth more than the per-employee cost, and an EOR earns its fee only when you have no entity where the worker sits. If neither test is met, neither model is worth the overhead.
Can you use both
Yes, and it is common. A US company can run its domestic team on a PEO, for pooled benefits and shared compliance, while using an EOR for the occasional international hire it cannot employ directly. The two models do not conflict; they cover different legal situations. The point is to match each worker to the structure their location requires, not to standardize on one for its own sake.
The bottom line
A PEO and an EOR both take employment administration off your desk. The difference is legal structure: a PEO co-employs a team you already legally employ, and an EOR becomes the legal employer where you have none. For a US company hiring in states where it is registered, a PEO is usually the fit, and NAPEO reports that businesses using a PEO grow about twice as fast as comparable firms that do not. An EOR is the tool for hiring where you have no entity, most often abroad. And when the workers are all where you already operate and you need little beyond payroll, neither may be necessary.
If you are weighing a PEO for your domestic team, request a consultation and we will connect you with our independent broker, who compares proposals matched to your size and states. The consultation is free to you. If you sign through the broker, he shares part of his fee with us. Expect the review to take several business days, not minutes.
Sources
- Internal Revenue Service, Third-party payer arrangements (Professional Employer Organizations; IRC section 3511; CPEO treated as employer for wages it remits).
- Internal Revenue Service, Certified Professional Employer Organization (CPEO) program.
- U.S. Department of Labor, Fair Labor Standards Act joint-employment guidance (joint employers jointly and severally liable for wages).
- NAPEO, State regulatory database (PEO registration and licensing by state).
- NAPEO, Industry Overview (PEO clients grow about twice as fast).
