When a PEO runs your payroll, the mechanics of federal employment tax filing change: returns can move off your employer identification number and onto the PEO's, filed in aggregate across all of its clients. Whether the liability moves with them is a separate question, and it is the one that matters when something goes wrong. Federal law gives a clear answer only for IRS-certified PEOs, and the paperwork that makes the arrangement official, Form 8973, has deadlines of its own. This page sets out the mechanics from the IRS's own guidance; the service agreement and the tax code control, and none of this is tax advice.
How a certified PEO files: aggregate returns and Schedule R
A certified professional employer organization files employment tax returns for its clients in aggregate under the CPEO's own EIN, attaching Schedule R to allocate the reported wages and taxes to each customer. The certification itself is an IRS status: the organization must apply, maintain a physical US business location, and demonstrate a history of financial responsibility, organizational integrity and tax compliance. One practical consequence the IRS states plainly: CPEO customers cannot view the federal tax deposits and payments the CPEO makes through the Electronic Federal Tax Payment System, so your visibility into whether deposits actually happened comes from the CPEO's reporting and the contract, not from EFTPS.
Certified vs everything else: where liability sits
For worksite employees under a CPEO contract, the IRS states that the CPEO is solely liable for paying the customer's employment taxes, filing returns, and making deposits and payments. That sole liability is the product certification exists to create. It is not unlimited: for remuneration a CPEO pays to non-worksite employees, the CPEO and the customer may both be liable, and the worksite definition comes from the revenue procedure, not from the sales deck. Outside certification the picture reverts to the IRS's general rule for third-party arrangements: payroll service providers and reporting agents do not assume liability, and the employer remains responsible for all of its federal employment tax duties even when a provider's failure caused the miss. A non-certified PEO's allocation of risk is whatever the contract says, backed by that default.
Form 8973: the paper trail that makes it official
The CPEO relationship is reported to the IRS on Form 8973, the CPEO/Customer Reporting Agreement. The CPEO must submit it within 30 days of a service contract starting, and again within 30 days of the contract ending, so the IRS knows exactly which periods the CPEO was responsible for. The contract itself must state the exact name and EIN of the CPEO fulfilling the federal employment tax obligations. For a buyer, those are checkable facts: ask for the filed Form 8973, confirm the named EIN matches the entity you signed with, and confirm the vendor appears on the IRS's published list of certified PEOs. A vendor that markets itself as a PEO but is not on that list is offering the ordinary third-party arrangement, with liability remaining yours.
What to verify before and during the relationship
Before signing: certification status against the IRS list, the exact EIN in the contract, and how the vendor handles state employment taxes, because certification is a federal program and state treatment varies by state. At the transition: how wage bases and filings are handled for the part-year before the PEO took over, since filings move between EINs mid-year. During the relationship: insist on regular proof of deposits and filings, because EFTPS will not show you the CPEO's payments. And at exit: the same 30-day Form 8973 mechanics run in reverse, and you resume filing under your own EIN from a defined date. Each of these is a place where a missed detail becomes a tax notice a year later.
Questions people ask about peo tax filing
If the PEO fails to pay the taxes, is my company still on the hook?
Under a CPEO contract, for worksite employees, the IRS holds the CPEO solely liable. With a non-certified PEO or any payroll service provider, the IRS's position is that the employer's duties remain its own, so yes, the exposure is generally yours.
What is Form 8973?
The reporting agreement that tells the IRS a CPEO contract has started or ended, due within 30 days each way. It is what ties your company to the CPEO's aggregate filings for the covered periods.
Whose EIN appears on Form 941 under a PEO?
A certified PEO files aggregate returns under its own EIN with Schedule R allocating amounts per client. Under ordinary payroll service arrangements, returns stay under your EIN.
Can I check that the PEO actually deposited the taxes?
Not through EFTPS; the IRS notes CPEO customers cannot see the CPEO's deposits there. Build proof-of-deposit reporting into the contract and ask for it on a schedule.