THE 60-SECOND ANSWER
A Paychex quote for a 25-person company opens at $45-$79/month base in 2026. The actual year-one invoice runs $3,840-$6,200 once per-employee fees, multi-state surcharges, and year-end W-2 processing land. I have audited payroll contracts across 30+ companies in SaaS, professional services, restaurants, and manufacturing. The advertised price is the floor. The invoice is the ceiling. This article builds the line-item math no vendor sends you.
Payroll outsourcing costs a US small business $2,388 to $37,500 per year in 2026. The range is not because vendors are inconsistent. It is because “payroll outsourcing” covers three completely different service categories that compete for the same keyword. Self-service software is $2,388/year at 25 employees. Fully managed payroll is $4,500-$8,500. A PEO arrangement with full co-employment lists at $23,700-$32,700 before benefits savings offset it.
When I audit a client’s payroll contract, I check four numbers: the base fee, the per-employee rate, the run fee, and the year-end W-2 charge. Most contracts advertise one of those four. Most invoices contain all four plus three more nobody mentioned during the sales call.
This is the breakdown I build before any client budget meeting. Three company sizes. Every cost annualized. Every hidden fee named. The number at the top of the page is the floor. Here is what you actually pay.
The Four Numbers Every Payroll Quote Is Actually Made Of
Payroll outsourcing pricing has four components: base fee, per-employee monthly fee, per-run fee, and year-end W-2 charges. Most vendors only advertise the first one.
The base fee is the monthly platform charge. It ranges from $35/month (Square Payroll) to $150+/month for fully managed services. This is the number on the pricing page.
The per-employee-per-month (PEPM) fee ranges from $4/employee at the entry tier to $25/employee for full-service. For a 25-person company, that line alone runs $100-$625/month before anything else.
The per-run fee is charged each time payroll processes. Most vendors do not display this prominently. A company running bi-weekly payroll (26 runs/year) at $5-$15/run pays $130-$390/year in run fees. Weekly payroll doubles that.
The year-end charges are W-2 and 1099 processing fees billed in January. Industry range: $3-$8 per form. A 25-person company with all W-2s pays $75-$200 in a year-end invoice most CFOs did not budget for.
The advertised price is the floor. The invoice is the ceiling.
What You Will Actually Pay at 10, 25, and 75 Employees
If you need one table before the deep dive, this is it. Verified pricing from live vendor pricing pages, April 2026.
| Provider | Base/Mo | PEPM | 10 Emp/Yr | 25 Emp/Yr | 75 Emp/Yr | Category |
|---|---|---|---|---|---|---|
| OnPay | $49 | $6 | $1,308 | $2,388 | $5,988 | Self-service |
| Gusto Simple | $49 | $6 | $1,308 | $2,388 | $5,988 | Self-service |
| Square Payroll | $35 | $6 | $1,140 | $2,220 | $5,820 | Self-service |
| Justworks Payroll | $50 | $8 | $1,560 | $3,000 | $7,800 | Self-service |
| Gusto Plus | $80 | $15 | $2,760 | $5,460 | $14,460 | Self-service + HR |
| Paychex Flex | Quote only | ~$2,400-$3,600 | ~$3,840-$6,200 | ~$9,000-$14,000 | Managed | |
| ADP Run | Quote only | ~$2,500-$3,800 | ~$4,400-$6,900 | ~$10,000-$15,000 | Managed | |
| Justworks PEO Basic | $0 | $79 | $9,480 | $23,700 | $71,100 | PEO |
| Justworks PEO Plus | $0 | $109 | $13,080 | $32,700 | $98,100 | PEO |
Pricing verified April 2026. OnPay $49 + $6/person. Gusto Simple $49 + $6, Plus $80 + $15. Square $35 + $6. Justworks Payroll $50 + $8, PEO Basic $79/emp, PEO Plus $109/emp. Paychex and ADP are quote-based; ranges reflect practitioner experience with 25-person accounts in Q1 2026. Figures exclude year-end W-2, off-cycle runs, and multi-state surcharges — those are covered in the next section.
That $29,112 spread between OnPay at $2,388/year and Justworks PEO Plus at $32,700/year for the same 25-person company is not a feature gap. It is a category gap. One is payroll processing software. The other is co-employment where Justworks becomes the employer of record and absorbs the compliance liability. Read our payroll software comparison for the software-only evaluation, and our multistate payroll software guide if your employees span more than two states.
Every payroll contract I have audited contains charges that were never mentioned in the sales conversation. These are not surprises. They are in the contract. They are just not in the quote.
Year-End W-2 and 1099 Processing
W-2 and 1099 fees are almost universally billed as a separate year-end invoice, not included in monthly quotes. Industry range: $3-$8 per form.
At 25 employees, budget $75-$200 in January for this line. At 75 employees, $225-$600. Gusto, OnPay, and Square Payroll include W-2 filing in base pricing. QuickBooks Payroll Core charges per form unless you upgrade to Premium.
Multi-State Tax Filing Surcharges
Any company with remote employees in multiple states triggers additional per-state tax filing fees. Gusto Simple charges $12/month per additional state. OnPay and Square include multi-state at no extra cost.
ADP and Paychex do not publish multi-state pricing. In my practice advising companies with employees in 3-5 states, I see $15-$25/state/month in surcharges on managed payroll arrangements. That is $540-$1,500/year in fees that appeared nowhere in the base quote.
Off-Cycle Payroll Run Charges
Off-cycle runs (termination checks, correction runs, bonus payments) are billed separately. Typical range: $25-$50 per run at major providers.
A company doing 8-10 off-cycle runs per year adds $200-$500 in unbudgeted fees. Terminations alone can trigger 6-8 off-cycle runs at a 50-person company.
Garnishment Processing Fees
Wage garnishment processing (child support, IRS levies, creditor garnishments) is charged per garnishment per pay period at most vendors. Typically $5-$15 per garnishment per run.
One employee with an active garnishment on a bi-weekly schedule costs $130-$390/year in processing fees most buyers never asked about. At a 50-person company, 2-3 active garnishments is common.
Combined, these four fee categories add $500-$2,000 per year to a 25-person company’s actual invoice. None of it appears in the advertised price. For a deeper look at how these patterns repeat across HR platforms, read our HR software hidden costs breakdown.
The Real Cost Comparison: In-House With Software vs Fully Managed
The in-house comparison is where most CFO conversations get stuck. Every competitor article compares “manual spreadsheet payroll” against “outsourced software” to make the ROI case. That is apples to bowling balls. No 25-person company in 2026 runs payroll on spreadsheets.
The honest comparison is in-house with software vs fully managed payroll service. Both use software. The difference is who clicks the buttons.
A US HR coordinator at the BLS median costs approximately $28/hour base, or $36.40/hour fully loaded at 1.3x for benefits and payroll taxes. That is the real rate, not the hourly salary.
On a modern self-service platform (Gusto, OnPay), a 25-person bi-weekly payroll takes 2-3 hours per run once the system is configured. That is review, approval, corrections, and exception handling. The software does the math and filing automatically.
At 2.5 hours per run x 26 runs x $36.40/hour loaded = $2,366/year in HR time. Plus the $2,388/year Gusto or OnPay subscription. Total in-house loaded cost: $4,754/year at 25 employees.
Fully managed payroll (Paychex, ADP Run) runs $4,500-$8,500/year for the same 25 people. The managed vendor processes the run, so HR time drops to 30-60 minutes per run for data review. That is $474-$948/year in internal time on top of the subscription. Total managed cost: $4,974-$9,448/year.
The honest conclusion: at 25 employees, self-service software plus 2-3 HR hours per run costs roughly the same as fully managed payroll. The decision is not about dollars. It is about whether that HR time is available and whether the person running payroll is comfortable being the liable party when something goes wrong.
The error layer changes the calculation. IRS failure-to-deposit penalties for Form 941 range from 2% (1-5 days late) to 15% (after IRS demand notice) per IRS Publication 15, 2026. A 5-day late deposit on a $50,000 quarterly payroll tax costs $1,000 at the 2% rate.
One missed state unemployment filing in my practice last year cost a 30-person company $4,200 in penalties, interest, and catch-up fees. That is where the managed premium pays itself back — the vendor absorbs that penalty under their tax guarantee.
The ROI math favors outsourcing only at two specific triggers: when your HR bandwidth is already saturated, or when you have had a compliance error in the last 24 months. At a stable 25-person company with an operations manager handling payroll competently, self-service software is the lower-total-cost answer. For companies past 50 FTE where ACA 1095-C reporting and EEO-1 filings enter the picture, our HR and payroll compliance software guide covers which platforms handle those filings without requiring full outsourcing.
Self-Service vs Fully Managed vs PEO: Where the Real Cost Gap Lives
Buyers conflate these three categories constantly. The pricing difference is not about features. It is about who is liable when payroll is wrong on Friday.
Self-service (Gusto, OnPay, Square, Justworks Payroll)
You configure the platform. You enter employee data. You approve runs. The software files taxes automatically, but you are liable for errors caused by your configuration. Annual cost for 25 employees: $2,220-$3,000.
This is the right category if you have an HR coordinator or operations manager who can own the platform day-to-day. For most companies under 50 employees, self-service is the correct answer.
Fully managed (Paychex Flex, ADP Run, Paylocity)
A dedicated payroll specialist processes runs on your behalf. Includes compliance monitoring, tax filing, garnishment handling, year-end forms. Annual cost for 25 employees: $4,500-$8,500 based on quotes I have seen for 25-person accounts in 2026.
This tier is right for companies without internal HR who need a human accountable for error liability. The premium over self-service is the human, not the software.
PEO and co-employment (Justworks, TriNet, Insperity)
The PEO becomes the employer of record for tax purposes. Your employees are legally employed by the PEO, which handles all state registrations, tax filings, benefits administration, and workers’ compensation. Justworks PEO Basic is $79/employee/month. PEO Plus is $109/employee/month.
For a 25-person company at Justworks PEO Basic, that is $23,700/year. At PEO Plus, $32,700/year. On paper, that looks like an enormous premium over self-service software. That framing is wrong and costs companies real money.
The PEO financial math nobody shows you
The PEO price tag is not the actual cost. PEOs pool your employees into their master health insurance plan and negotiate large-group rates you cannot access as a 25-person company buying direct from a broker. The savings typically run $500-$1,500 per employee per year in health insurance premium differential alone.
At 25 employees, that is $12,500-$37,500/year in health insurance savings. That number roughly equals or exceeds the PEO fee itself.
Workers’ compensation is the second big savings line. Buying WC insurance direct requires an annual premium deposit based on estimated payroll. PEOs run pay-as-you-go WC, eliminating the deposit and smoothing cash flow. Typical savings: $2,000-$5,000/year for a 25-person company, plus freed-up working capital from the eliminated deposit.
401(k) administration is included in most PEO plans. Running a standalone 401(k) costs $30-$60 per employee per year in admin fees, or $750-$1,500/year at 25 employees. Benefits brokerage fees (typically 3-5% of premium when buying direct) also go away under a PEO arrangement, saving another $1,500-$3,000/year.
Adding it up for a 25-person company at Justworks PEO Basic:
- PEO fee: $23,700/year
- Health insurance savings: $12,500-$37,500/year
- Workers’ comp savings: $2,000-$5,000/year
- 401(k) admin savings: $750-$1,500/year
- Benefits brokerage savings: $1,500-$3,000/year
Net PEO cost after savings: often $0-$5,000/year above the self-service alternative. For some companies with expensive local insurance markets, the PEO is genuinely cheaper than going direct. This is the math that turns PEO from “the expensive option” into “the hidden value option” for the right buyer.
PEOs are the right answer for companies under 50 employees in expensive health insurance states (California, New York, Massachusetts), companies entering high-complexity states for the first time, or founders who want compliance liability entirely off their plate. They are the wrong answer for companies with cheap existing group plans they negotiated when they were bigger.
I always ask clients one question before recommending a tier. If payroll is wrong this Friday, who owns that call with the employee? If the answer is uncertain, you need fully managed or PEO. If the answer is a named person internally, self-service is fine.
How Payroll Outsourcing Costs Change as You Scale
Cost structure shifts as you grow. Understanding which components scale linearly and which step up in tiers tells you where renegotiation is possible.
The base fee stays flat or increases by one tier jump (Gusto Simple to Plus, for example). Usually a one-time step, not a continuous increase.
The PEPM fee scales linearly. Every new employee adds the full per-employee cost. At $6/employee/month, each hire adds $72/year. At $15/employee/month on Gusto Plus, each hire adds $180/year.
The run fee scales with pay frequency, not headcount. A company switching from monthly to bi-weekly payroll doubles its run fee cost without hiring anyone. Switching to weekly doubles it again.
The multi-state fee scales with state count, not headcount. Distributed hiring is the cost accelerant companies do not see coming.
The SaaS price increase factor applies to every payroll contract I have reviewed. Vendors raise prices 5-10% annually, often uncapped. A base fee of $200/month today reaches $266/month in three years at 10% annual compounding.
The scaling fee that catches companies off guard is almost always the run fee, not the PEPM. When a 20-person company switches from monthly to bi-weekly payroll to improve employee satisfaction, the payroll bill jumps 25-40% with zero new hires.
How to Read a Payroll Outsourcing Quote Before You Sign
The reader has a vendor quote or is about to get one. This is the framework I use when auditing those quotes.
Ask for the all-in quote, not the base quote. Tell the vendor: “I need a quote that includes base fee, per-employee fee at X employees, bi-weekly run fee, state tax filing for N states, year-end W-2 processing, and garnishment handling. Please line-item each.” Any vendor who will not provide this in writing is pricing strategically against you.
The four questions to ask every vendor before signing:
- “What is your per-run fee, and does it change if I switch payroll frequency?”
- “What do you charge for W-2 and 1099 processing, and is that included in my monthly fee or billed separately?”
- “What is the per-state fee for multi-state tax filing, and at which plan tier does multi-state become available?”
- “What are your off-cycle run fees for termination checks and corrections?”
The calculation to run before signing: Take the monthly quote × 12 + estimated run fees + W-2 fees + expected off-cycle runs. That is your Year 1 total. Apply a 7.5% annual increase (midpoint of the 5-10% SaaS norm) for Year 2 and Year 3. Compare the three-year total against the in-house loaded labor number.
The negotiation window. Multi-year contracts (2-3 years) often unlock 10-20% discounts on PEPM fees, especially for accounts above 25 employees. Request this before signing, not at renewal. ADP and Paychex discount 15-20% in the final week of each quarter because of sales quota pressure.
How Much Does Payroll Outsourcing Actually Cost for a Small Business?
Payroll outsourcing costs a US small business $1,308 to $23,700 per year at 10-25 employees depending on service tier. Self-service software runs $1,308-$3,000/year at 10-25 employees. Fully managed payroll runs $2,400-$6,200. PEO arrangements run $9,480-$32,700 for the same headcount.
On a per-employee basis, expect $6/employee/month for self-service software, $15-$25/employee/month for fully managed services, and $79-$109/employee/month for PEO co-employment. The service difference is who is liable when the filing is wrong.
These figures cover US-based W-2 payroll. Multi-state workforces add $0 (OnPay, Square, Gusto Plus) to $12/month per extra state (Gusto Simple). Companies with active garnishments or frequent off-cycle runs pay an additional $500-$2,000/year in add-on fees that do not appear in advertised pricing.
Frequently Asked Questions: Payroll Outsourcing Cost 2026
How much does it cost to outsource payroll for a small business?
For a 10-25 person company, payroll outsourcing costs $1,308-$3,000/year on self-service platforms like OnPay or Gusto Simple ($49 base + $6/employee/month). Fully managed services like Paychex or ADP run $2,400-$6,200/year at the same headcount. PEO arrangements like Justworks cost $9,480-$23,700/year at the same size range.
What is the average cost per employee for payroll outsourcing?
Per-employee-per-month rates range from $6/employee for self-service platforms (Gusto Simple, OnPay, Square Payroll) to $15-$25/employee for fully managed services. PEO arrangements charge $79-$109/employee/month including benefits administration and compliance. Negotiated volume rates can reduce PEPM fees by 15-20% for accounts above 50 employees.
Is it cheaper to do payroll in-house or outsource it?
In-house with software and managed payroll cost roughly the same at 25 employees in 2026. In-house on Gusto or OnPay costs $2,388/year in subscription plus $2,366/year in HR time (2.5 hours per bi-weekly run at $36.40/hour loaded) = $4,754/year total. Fully managed payroll runs $4,500-$8,500/year. The decision comes down to HR bandwidth and liability preference, not dollars. Outsourcing is meaningfully cheaper only when you have had a compliance error in the last 24 months or your HR bandwidth is already saturated.
What hidden fees should I look for in a payroll outsourcing contract?
The four most commonly unlisted fees are year-end W-2 and 1099 processing ($3-$8/form), per-state tax filing for multi-state employees ($15-$25/state/month on managed plans), off-cycle payroll run charges ($25-$50/run), and garnishment processing ($5-$15/garnishment/run). Combined these add $500-$2,000/year to a 25-person company’s invoice.
What is the difference between payroll software and PEO outsourcing?
Payroll software (Gusto, OnPay) processes payroll on your behalf but you remain the employer of record and retain compliance responsibility. A PEO like Justworks co-employs your staff as the legal employer of record, handling state registrations, tax filings, and benefits administration. PEOs cost $79-$109/employee/month versus $6-$15/employee/month for software, but transfer compliance liability entirely to the PEO.
Does outsourcing payroll include tax filing?
Most full-service payroll platforms including Gusto, OnPay, and Paychex file federal and state taxes automatically. Patriot Basic and QuickBooks Payroll Core have limitations at the lowest tier. Multi-state tax filing, local tax jurisdictions (Philadelphia wage tax, NYC local income tax), and year-end W-2 distribution are often add-ons or plan-tier dependent. Always confirm which filings are included at your specific state footprint.
The decision comes down to three questions. First, who owns the call if payroll is wrong on Friday? Second, how many states will you run payroll in within 12 months? Third, is your priority cost minimization or compliance risk transfer? For answers one and two, compare your current answer to the payroll outsourcing category for vendors that match your profile. For the compliance question, PEO makes sense only if the answer is “transfer the liability entirely.”
Backed by real discussions, real experiences, and real outcomes from teams like yours.
