Best Payroll Software for CPA Firms
For a CPA firm, Gusto is the best default payroll platform: full-service federal, state, and local filings at a published $49/month plus $6 per person, with a client-facing experience that doesn't route problems back to your staff. OnPay is the better standard when your client mix skews multi-state, because it includes multi-state payroll in its flat $49/month plus $6 per person.
A firm's calculus differs from a bookkeeping shop's in one important way: liability. Which entity is on the hook for a late deposit or a wrong filing determines what plan you should be putting clients on, and it should be settled in your engagement letter before the platform decision matters.
The picks below reflect that. Full-service filing coverage is weighted heavily, self-service plans are treated as a deliberate exception rather than a cost saving, and quote-based providers are named as quote-based.
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Our ranked picks
We earn a commission from Gusto, OnPay, ADP, and Patriot, and nothing from Paychex. Rank order follows documented capability and firm-level fit.
- 1Best firm-wide default
Gusto
Firms standardizing most clients on one predictable platform
Gusto gives a firm the two things it needs most: predictable published pricing to build into client fees, and full-service filings so payroll compliance isn't sitting in your staff's inbox. Simple is $49/month plus $6 per person; Plus is $80/month plus $12 per person and adds multi-state, time tracking, and next-day direct deposit.
Client self-service is the underrated part. Employees enter their own details and access their own pay stubs and W-2s, which cuts a recurring category of client requests out of your workflow entirely.
Where it falls short- Multi-state clients need Plus, so the per-client cost isn't uniform across your book.
- Premium is quote-based.
- No dedicated support rep assigned to the firm by default.
- being verified: confirm Gusto's current accountant partner program terms before building them into firm pricing.
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- 2Best for multi-state client mixes
OnPay
Firms whose clients regularly hire across state lines
One plan, $49/month plus $6 per person, with multi-state payroll, unlimited pay runs, federal, state, and local filings, and W-2 and 1099 filings included. For a firm, that means a single quotable number regardless of how a client's footprint changes.
Benefits in supported states, 401(k) integrations, and workers' comp are available in the same plan, so a client's growth doesn't automatically trigger a platform migration.
Where it falls short- Interface and employee experience are more utilitarian than Gusto's.
- No contractor-only tier for 1099-only clients.
- Fewer integrations than the larger platforms.
- being verified: confirm OnPay's current accountant partner program and multi-client access.
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- 3Best for larger and more complex clients
ADP RUN
Clients whose payroll has outgrown small business platforms
ADP RUN steps from Essential Payroll through Enhanced, Complete Payroll & HR Plus, and HR Pro, adding SUI management, an HR help desk, and HR advisory, with room to move further up ADP's line as a client scales. For complex clients, that ceiling matters.
For a firm, there's also the operational reality that your staff and your clients' prior accountants can already read ADP's reports and registers, which shortens onboarding and cleanup work.
Where it falls short- Quote-based pricing complicates fixed-fee client engagements.
- Add-on charges accumulate across tiers and modules.
- Interface is dated relative to newer platforms.
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- 4Best for clients who want a named specialist
Paychex
Clients who prefer calling a person over using software
Paychex Flex Essentials covers full-service payroll and tax filing, Select adds a dedicated payroll specialist, and Pro layers in onboarding, workers' comp, and an HR library. For the client who will call someone regardless, it's better that they call Paychex than your firm.
We earn nothing from Paychex. It's here because the dedicated-specialist model genuinely reduces the support load a firm absorbs on certain clients.
Where it falls short- Quote-based, so no comparable published rate.
- The dedicated specialist requires the Select tier or above.
- Generally more expensive than published-price platforms at small headcount.
- 5Best when the firm keeps the filings
Patriot Payroll
Engagements where your firm files the payroll taxes
Patriot is the honest choice for the specific engagement where your firm has taken on filing responsibility. Basic Payroll handles the calculations and pay stubs at a very low base price and leaves the filings and deposits with you; Full Service hands the filings back to Patriot with a tax filing accuracy guarantee.
Its low base price also makes it the practical option for very small clients where a $49 base is a meaningful share of the payroll itself.
Where it falls short- Basic Payroll shifts filing liability — make the split explicit in the engagement letter.
- Limited benefits and HR functionality if a client grows.
- Basic Payroll is $17/month plus $4 per worker paid, but you handle the tax filings and deposits yourself; Full Service Payroll is $37/month plus $5 per worker paid (pricing verified August 2026).
- being verified: confirm Patriot's current accountant program and multi-client management features.
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Compare the picks side by side
| Provider | Starting price | Per person | Best for |
|---|---|---|---|
| Gusto | Simple: $49/mo base | $6 / person / mo | Firms standardizing most clients on one predictable platform |
| OnPay | $49/mo base | $6 / person / mo | Firms whose clients regularly hire across state lines |
| ADP RUN | Quote-based | Quote-based | Clients whose payroll has outgrown small business platforms |
| Paychex | Quote-based | Quote-based | Clients who prefer calling a person over using software |
| Patriot Payroll | Full Service: $37/mo base | $5 / worker paid / mo | Engagements where your firm files the payroll taxes |
Prices shown come from each provider's review page on this site. Confirm current pricing with the provider before signing up — payroll pricing changes often.
Pricing verified August 2026
How we picked
For CPA firms we weight filing liability first. A platform that files federal, state, and local payroll taxes moves a strict deadline obligation away from your staff, and that is worth more than any monthly price difference across a book of clients.
Second, pricing predictability, because fixed-fee engagements break when a payroll vendor's cost is only knowable via a sales call. Third, client self-service and onboarding speed, since those determine how many client-initiated tasks land on your team every month.
We treat self-service payroll as a deliberate professional choice, not a discount — appropriate only when your engagement letter says the firm is filing. Partner-program terms are marked as items to verify rather than restated, because they change often.
Every provider is scored against the same criteria. Read our payroll software review methodology.
Frequently asked questions
What is the best payroll software for a CPA firm?
For most firms, Gusto: published pricing at $49/month plus $6 per person on Simple, full-service federal, state, and local filings, and client self-service that keeps routine requests off your staff. OnPay is the better firm-wide standard if your clients frequently pay employees in more than one state.
Should my firm take on payroll tax filing responsibility?
Only deliberately, and only in writing. Full-service platforms like Gusto, OnPay, and Patriot's Full Service plan file federal, state, and local payroll taxes for you, which keeps deadline risk with the provider. Self-service plans such as Patriot's Basic Payroll leave that obligation with whoever your engagement letter names.
How should a firm price payroll services to clients?
It's easiest with published-price providers, because your cost is knowable: Gusto is $49/month plus $6 per person on Simple, and OnPay is $49/month plus $6 per person with multi-state included. Quote-based providers like ADP and Paychex are harder to fold into a fixed monthly fee.
Which platform is best for a client with employees in several states?
OnPay among the published-price providers, since multi-state payroll is included in its flat $49/month plus $6 per person. Gusto handles multi-state on the Plus plan at $80/month plus $12 per person.
Is it worth using different payroll platforms for different clients?
Some variation is unavoidable — QuickBooks Online clients, very large clients, and clients who insist on a dedicated rep all pull in different directions. But every additional platform adds training and support cost, so keep the exceptions few and justified.
The bottom line
Pick one firm-wide default — Gusto for most books, OnPay for multi-state-heavy books — and keep ADP or Paychex for the clients who genuinely need a quote-based, service-led relationship.
Then settle the liability question in your engagement letters before you migrate anyone. The platform is the easy part; who owns the filing deadline is the part that costs money when it's ambiguous.
Read how we research and score payroll providers in our payroll software review methodology.