Payroll & HR Outsourcing for SMBs: A Guide

Jan de Vries · 2026-05-22

So you're running a small to mid-size business in the U.S., and you've got between 10 and 200 employees. Payroll, benefits, compliance—it's a lot. You know you need help, but the options sound like alphabet soup: PEO, ASO, EOR, HCM. What do you even pick? Here's the simple truth: the right choice depends on who you want to be the legal employer, who files your taxes, and where your people work. This guide breaks down each model, names real providers, shows you real pricing, and gives you a framework you can use to compare them side by side. ### What You're Really Choosing Let's cut through the jargon. There are four main ways to outsource payroll and HR. They differ in three key ways: who employs the worker, who files payroll taxes, and where the work happens. Get this wrong, and you'll overpay or end up with a setup that doesn't fit. **PEO (Professional Employer Organization):** This is a co-employment arrangement. The PEO becomes a co-employer, files payroll taxes under its own EIN, and pools your employees into its benefits plans. Over 230,000 U.S. businesses use a PEO, covering about 4.5 million workers. Look for IRS Certified PEO (CPEO) status and ESAC accreditation—that means they've passed financial audits. **Payroll/HR Software (HCM):** Here, you stay the sole employer. The software handles payroll, time tracking, benefits admin, and compliance tools as modules, but it files taxes under your EIN. HCM stands for Human Capital Management—it's the software layer for employee data and workflows. **ASO (Administrative Services Organization):** Think of this as advisory and admin support without co-employment. You stay the employer, and the ASO helps with things like payroll admin, handbook updates, or compliance advice. Services are usually sold a la carte. **EOR (Employer of Record):** This is for hiring internationally. The EOR becomes the legal employer in the foreign country, so you can hire someone in, say, Germany, without opening a local entity. A PEO requires you to have a domestic entity. An EOR removes that requirement entirely.  ### When to Use Each Model Start with your legal footprint. Where are your employees located? How much control do you want to keep? Match the model to your current reality, not your dream state. Here's a quick cheat sheet: - **PEO:** Best when all your employees are U.S.-based and you want one bundled admin layer. You share employer responsibilities. - **Payroll/HR Suite:** Best when you have an internal HR person and want full control. You keep all employer responsibilities. - **ASO:** Best when you only need expert advice and admin help, not co-employment. - **EOR:** Best when you're hiring someone abroad and have no legal entity in that country. > A simple test: If everyone is in the U.S. and you want one bill, compare PEOs. If you want software and full control, compare payroll suites. If you only need a consultant, ask ASO firms. If one hire is overseas, start with an EOR.  ### Cost Models You Should Expect Don't just look at the admin fee. Separate admin fees from pass-through costs (like benefits premiums and workers' comp). The lowest admin fee can still produce the highest total cost. **PEO pricing:** Flat fee per employee per month (PEPM) or a percentage of gross payroll. Justworks publishes two tiers: around $59 and $99 per employee per month for smaller teams. Oyster's U.S. PEO lists an $89 PEO fee plus a $25 platform fee per employee per month, plus a one-time $500 implementation fee. ADP TotalSource and Paychex PEO are quote-based. **Payroll/HR suites:** Transparent base plus per-person fees are common. Gusto's Simple plan is $49 per month plus $6 per person. Higher tiers add deeper HR features. **EOR pricing:** Expect higher fees because the provider becomes the legal employer abroad. Deel starts at $599 per employee per month. ### How to Compare Providers When you're ready to evaluate, use this framework. Ask every vendor these three questions: 1. Who is the legal employer of my workers? 2. Under whose EIN are payroll taxes filed? 3. What is the total cost per employee per month, including all pass-through fees? Get the answers in writing. Then compare apples to apples. That's how you avoid a bad purchase. ### Final Takeaway You don't need to be an HR expert to make this decision. Just know your footprint and your control preference. Use the right model for your situation, and you'll save time, money, and headaches.