In-House vs Outsourced Payroll at 10, 25 and 50 Employees: The Real Monthly Cost

Written & reviewed by Ram Singh, founder, Numerawise Solutions · Last reviewed September 3, 2026

At 10 employees, running payroll in-house costs roughly $500 a month once you price the admin hours honestly, against about $200 outsourced. At 25 it is roughly $700 against $360. At 50 the gap narrows to roughly $1,100 against $840, and the deciding factor becomes penalty exposure rather than fees. The worked numbers, the sources behind them, and the formula to substitute your own are below.

The inputs, and where each one comes from

• Loaded hourly rate. BLS Occupational Employment and Wage Statistics (May 2025) puts the mean wage for payroll and timekeeping clerks at $28.67 an hour and for bookkeeping, accounting and auditing clerks at $25.75. The BLS Employer Costs for Employee Compensation release for March 2026 puts benefits at 30.1% of total compensation in private industry, so a $28.67 wage costs the employer about $41 an hour loaded. If the owner runs payroll, substitute whatever an hour of the owner’s time is worth; it is rarely less.
• Hours per pay run. No government source publishes this, so it is our assumption and you should replace it with a stopwatch: 2 hours per run at 10 employees, 3.5 at 25 and 6 at 50, on a semi-monthly schedule (24 runs a year). That covers collecting hours, entering changes, reviewing, approving, and answering the questions that follow every run.
• Compliance hours. The IRS’s own Paperwork Reduction Act estimate in the Form 941 instructions gives the average Form 941 filer 62 hours a year of recordkeeping, learning and preparation across 941s and W-2 activities. We use that figure unchanged at all three headcounts.
• Software. Vendor list prices as published on their pricing pages at the time of writing: QuickBooks Workforce Payroll (payroll only) $50 a month plus $7 per employee; Gusto Simple $49 plus $6. Promotional first-months pricing is ignored because you do not pay it in month four.
• Outsourced. Our own published payroll pricing: Standard at $120 a month plus $8 per employee for 6–25 employees, Growth at $280 plus $10 for 26–100. We add the owner’s approval time at the same $41 rate — 20, 30 and 45 minutes per run — because outsourcing does not make it zero.

The worked numbers

Swapping Gusto Simple for QuickBooks changes the in-house software line by $11 to $51 a month and none of the conclusions. The lines that move the answer are the two hours rows, which is exactly why the software-versus-fee comparison misleads: at 10 employees the person costs three times the subscription.

Notice the shape at 50. The fee gap narrows because our Growth tier is priced for the added complexity of a larger workforce, and because a 50-person company often has an admin who would be employed anyway. If that person’s payroll hours are genuinely marginal — they would otherwise sit idle — in-house at 50 can be cheaper on fees alone. That is where the next section decides it.

The line that is not on the table: penalty exposure

Employment-tax penalties fall on the employer. IRS’s Trust Fund Recovery Penalty page states the penalty is equal to the unpaid balance of the trust fund tax, assessed personally on responsible persons, and it lists payroll service providers and PEOs among those who can be responsible without lifting that exposure from you. So outsourcing does not transfer the risk; it changes who is watching the calendar. Price the risk anyway, because it is where an in-house payroll goes wrong.

• Failure to deposit (IRS.gov, reviewed February 2026): 2% of the deposit if 1–5 days late, 5% at 6–15 days, 10% beyond 15 days, and 15% if still unpaid more than 10 days after the first notice. The tiers replace each other; they do not stack.
• Deposit schedule (Publication 15, 2026): more than $50,000 of employment tax reported in the July–June lookback period makes you a semiweekly depositor, and $100,000 accumulated on any single day is due the next business day whatever your schedule. A 50-employee payroll is almost always semiweekly; a 10-employee payroll is often monthly. Headcount changes the calendar, and the calendar is where deposits get missed.
• Failure to file / failure to pay on Form 941 (Publication 15): 5% of unpaid tax per month up to 25% for not filing; 0.5% per month up to 25% for not paying.
• W-2s (General Instructions for Forms W-2 and W-3, filings due after December 31, 2026): $60 per form if corrected within 30 days, $130 through August 1, $340 after that, with small-business caps of $244,500, $698,500 and $1,397,000 respectively, and at least $690 per form for intentional disregard. A parallel penalty applies for not furnishing the copy to the employee, so one late batch can be penalized twice.

Put one number on it. A 50-employee company depositing roughly $25,000 per semi-monthly run that lets one deposit slip past 15 days owes a 10% penalty of about $2,500 — three months of the outsourced fee, from a single miss. At 10 employees the same miss on a $4,000 deposit costs $400, which is two months of fees. The in-house column above carries that exposure at full weight; the outsourced column carries it with someone whose only job is not to miss.

Run it with your own numbers

1. Time three pay runs end to end, including the questions afterward. Multiply the average by your runs per year.
2. Add 62 hours for filings, or your own figure if you track it.
3. Multiply by the loaded rate of whoever does it: wage ÷ 0.699 approximates the BLS benefits share, or use the owner’s hourly value.
4. Add the software list price at your headcount, not the promotional price.
5. Add one realistic penalty a year at your deposit size — the 5% tier is the honest assumption for a busy office.
6. Compare against the quote, plus your own approval time. Our small-business payroll and outsourced payroll pages describe what the fee covers, and the quote arrives within 24 hours of a call.

If step 6 comes out in favour of in-house, keep it in-house; the point of the exercise is the arithmetic, not the answer. Most businesses under 25 employees find the person costs more than they thought, and most above 50 find the deposit calendar is the part they most want off their desk.

Frequently asked questions

How much does in-house payroll really cost for 10 employees?

About $500 a month when you include the admin hours. Using BLS wage data for payroll clerks, loaded for benefits, two hours per semi-monthly run plus the IRS's 62-hour annual compliance estimate come to roughly $376 a month, plus about $120 in software at list price. Outsourced, the same payroll is about $200 a month plus a few minutes of approval time.

Does outsourcing payroll remove my liability for payroll tax penalties?

No. The IRS states the Trust Fund Recovery Penalty equals the unpaid trust fund tax and can be assessed on responsible persons, and it names payroll service providers and PEOs as potentially responsible without removing the employer's exposure. Outsourcing changes who watches the deposit calendar; it does not transfer the liability.

What is the IRS penalty for a late payroll tax deposit?

Per IRS.gov, 2% if 1 to 5 days late, 5% at 6 to 15 days, 10% beyond 15 days, and 15% if still unpaid more than 10 days after the first IRS notice. The tiers replace each other rather than stacking.

At what size does in-house payroll become cheaper than outsourcing?

On fees alone, usually when an existing admin's payroll hours are genuinely marginal, which tends to happen around 50 employees. At that size, though, the company is almost always a semiweekly depositor, so the deciding factor becomes deposit-calendar risk rather than the monthly fee.