Key Takeaways
- A payroll company processes payroll and files taxes. A PEO provides payroll plus benefits, HR, workers' comp, compliance, and shared liability.
- Payroll companies do not provide access to group health insurance or workers' comp pooling.
- A PEO is a co-employer, while a payroll company is a vendor. This distinction affects liability and benefits access.
- If you only need paycheck processing, a payroll company is sufficient. If you need better benefits and compliance support, a PEO is the right choice.
What a Payroll Company Does
A payroll company, like ADP or Paychex in their basic configuration, processes your payroll. They calculate wages, withhold taxes, issue paychecks or direct deposits, file payroll taxes, and provide year-end W-2s. Some offer add-on services like benefits administration or HR support, but the core service is payroll processing.
A payroll company is a vendor. Your business remains the sole employer of record. You are responsible for all compliance, benefits negotiation, workers' comp, HR management, and employment law obligations. The payroll company handles the mechanics of paying employees, but nothing beyond that.
What a PEO Does Differently
A PEO does everything a payroll company does, plus significantly more. Through co-employment, the PEO becomes the employer of record for payroll, tax, and benefits purposes. This allows the PEO to pool your employees with thousands of others, giving you access to Fortune 500-level health insurance, dental, vision, 401(k), and workers' comp at large-group rates.
The PEO also provides HR infrastructure: employee handbooks, compliance documentation, I-9 management, ACA reporting, disciplinary support, and legal updates. The PEO shares liability for employment compliance, which is a level of protection a payroll company cannot offer. In short, a payroll company processes transactions, while a PEO manages the entire employer relationship.
The Benefits Access Gap
This is the most significant practical difference. A payroll company does not provide health insurance. You buy it on your own, at small-group rates, and the payroll company may administer it for a fee. A PEO provides access to its master health insurance plan, with rates negotiated across thousands of employees. The savings are typically 20 to 25 percent for small businesses.
The same applies to workers' comp. A payroll company may process your workers' comp payments, but you carry your own policy with your own experience modifier. A PEO carries a master workers' comp policy, and your employees are covered under the pooled plan with a blended experience modifier. For high-risk industries, this can reduce workers' comp costs by up to 25 percent.
Compliance and Liability
A payroll company files your payroll taxes, but you remain responsible for all employment compliance. If an audit finds I-9 violations, FLSA misclassification, or ACA reporting errors, you face the penalties. The payroll company is not liable. Some payroll companies offer HR support services, but these are advisory, not shared liability.
A PEO shares liability for employment compliance because of co-employment. The PEO is the employer of record for tax filings, I-9 compliance, and certain employment law obligations. This shared liability is a significant protection that a payroll company cannot provide. For businesses without dedicated HR or legal support, this is often the deciding factor.
When to Choose Each
Choose a payroll company if you have good benefits already, have internal HR support, only need paycheck processing, and want to keep costs minimal. A payroll company is a transactional service that handles the mechanics of paying employees without changing your employer infrastructure.
Choose a PEO if you want better benefits at lower cost, need HR and compliance support, want shared liability, have elevated workers' comp costs, or do not have dedicated internal HR. A PEO is a strategic partnership that transforms your employer infrastructure, not just a payroll processor. The decision comes down to whether you need payroll processing or a full employer services partner.
Frequently Asked Questions
Is a PEO just a more expensive payroll company?
No. A PEO provides services that a payroll company cannot, including group health insurance access, workers' comp pooling, HR infrastructure, and shared compliance liability. The higher fee is offset by savings on insurance and the value of liability protection. The right comparison is total cost of employment, not just the service fee.
Can I keep my payroll company and add a PEO?
Generally no. A PEO includes payroll processing as part of its service, so using both would be redundant and expensive. When you move to a PEO, the PEO takes over payroll processing. If you later leave the PEO, you can return to a standalone payroll company.
Does a PEO replace my HR person?
For many small businesses, yes. A PEO provides HR support, compliance documentation, employee handbooks, and legal guidance that an internal HR person would handle. For larger businesses, a PEO complements an internal HR person by handling benefits, compliance, and payroll, freeing the HR person to focus on culture and talent development.