AI payroll tool cost per employee: Gusto vs Rippling vs ADP Workforce Now vs Paychex Flex vs OnPay vs Justworks — what each one actually costs in June 2026

**Gusto** is what happens when designers build payroll software. It started as ZenPayroll in 2011 and grew into a full-service SMB platform that runs payroll, files federal/state/local taxes automatically, manages benefits, and now ships an AI compliance assistant that answers 'can I pay this contractor in California as a 1099?' in plain English. The Simple tier at $40/mo + $6/EE (https://gusto.com/product/pricing) covers W-2 and 1099 payroll, basic time tracking, and health benefits brokerage. It tops out around 100 employees before the UX starts feeling cramped — Gusto knows this, which is why Plus exists.

**Rippling** is a different category entirely. Parker Conrad's second act after Zenefits, it sells payroll as a single module inside a unified workforce platform that also covers IT provisioning (laptops, SaaS apps, SSO), HR, and Finance (spend management, corporate cards). The base Payroll module is roughly $8/EE/mo per https://www.rippling.com/pricing, which is the cheapest published number in this comparison — but you'll quickly add HR ($6/EE), Benefits ($6/EE), and IT ($8/EE) modules until your real bill is $25-40/EE/mo. That's the Rippling trade: cheap entry, expensive depth.

**ADP Workforce Now** is the incumbent. ADP processes one in six US private-sector paychecks. Workforce Now is the mid-market product (50-1,000 employees) covering payroll, HR, benefits, and talent. ADP doesn't publish prices — their pricing page (https://www.adp.com/what-we-offer/products/adp-workforce-now.aspx) routes you to a sales rep. Industry benchmarks put it at $60-180/mo base + $5-15/EE depending on modules. What you're paying for: 75 years of tax-filing expertise, certified payroll for government contractors, and a tax-research team that knows the SUTA rate in every county in America.

**Paychex Flex** is ADP's nearest peer, and the only major player that publishes entry-tier pricing: $39/mo + $5/EE for Flex Essentials per https://www.paychex.com/payroll/payroll-services-pricing. It quietly undercuts Gusto Simple by $1/mo and $1/EE. Paychex's edge is benefits — they're one of the largest 401(k) administrators in the country, and bundling benefits with payroll often nets better effective pricing than Gusto's brokerage model. The Flex Assistant chatbot handles common HR questions but is closer to a decision-tree than a real LLM.

**OnPay** is the no-BS option. One plan, $40/mo + $6/EE flat per https://onpay.com/pricing, includes all 50 states, all tax filings, multiple pay schedules, W-2s and 1099s, basic HR, and PTO tracking. There are no AI features, no chatbot, no recruiter module — just payroll that works. For a 10-person company that wants to know exactly what next month's bill will be, OnPay is the answer. They're the only vendor in this list with a real free trial (one month).

**Justworks** isn't a payroll tool — it's a PEO (Professional Employer Organization). You're technically co-employed by Justworks, which means they handle payroll, taxes, workers' comp, and benefits as the employer-of-record for compliance purposes. That's why pricing is $59-$99/EE/mo per https://www.justworks.com/pricing instead of base + per-EE — you're paying for benefits leverage and compliance offload, not software. For a 30-person startup that can't otherwise get group health rates, Justworks pencils out. For a 200-person company with its own benefits broker, it doesn't.

Every payroll vendor in 2026 claims AI. Most of it is a chatbot wrapping a knowledge base. **Gusto** ships the most useful real AI feature: an embedded compliance Q&A that answers state-specific labor law questions ('Do I need to give a final paycheck on the last day in Massachusetts?') with citations. It's powered by a Gusto-tuned LLM with their compliance team's playbook in the context window. Gusto also drafts offer letters, runs anomaly detection on payroll runs (flagging a contractor whose hours doubled), and auto-categorizes expense reimbursements. None of this is revolutionary — it's competent table-stakes AI.

**Rippling** went further. Their AI Recruiter (https://www.rippling.com/pricing) auto-screens candidates against job descriptions, schedules interviews, and drafts feedback summaries. The AI workflow builder lets you describe a process in English ('when a new sales hire starts, provision Salesforce + HubSpot + give them a $200 software stipend') and it builds the automation. The policy assistant generates employee handbooks from your company answers. This is the most ambitious AI surface area in the category — and it's the main reason Rippling's all-in price is high.

**ADP Assist** (https://www.adp.com) is ADP's GenAI layer, launched late 2024. It does three things well: natural-language search across payroll data ('show me everyone who got a raise in Q1'), anomaly detection on tax filings, and conversational reporting. It's enterprise-grade and audit-friendly. It does not write offer letters or build workflows — ADP is conservative about AI in employment contexts, partly because they have actual lawyers reviewing every feature.

**Paychex Flex Assistant** is a chatbot. It answers questions about your account and routes complex queries to humans. The 'AI insights dashboard' is mostly rule-based analytics with a GPT-style summary on top. This is the floor of what counts as AI in 2026, and Paychex prices accordingly — you're not paying extra for it.

**OnPay** has no LLM features. None. They have automation rules and they have a clean UI. If you want AI, OnPay is the wrong vendor. They've publicly said they'd rather get payroll right than ship AI features that hallucinate tax advice — a defensible position that I respect.

**Justworks** ships AI-powered support chat (24/7, handles ~60% of tickets per their 2025 report) and an AI benefits guidance tool that helps employees pick health plans during open enrollment. Both are useful inside the PEO model where benefits are the headline feature. Don't buy Justworks for the AI — buy it for the group health rates and W-2 compliance offload.

Sticker pricing means nothing until you plug in headcount. At **5 employees**, **Gusto** Simple is $40 + (5 × $6) = $70/mo, or $14/EE all-in. **OnPay** matches exactly at $70/mo ($14/EE). **Paychex Flex Essentials** comes in cheapest at $39 + (5 × $5) = $64/mo ($12.80/EE). **Rippling** Payroll-only is ~5 × $8 = $40/mo ($8/EE) but you almost never run Rippling without HR, which pushes it to ~$14/EE. **ADP Workforce Now** is overkill at 5 EE — they'd quote you ~$110-130/mo ($22-26/EE), and you'd be better off on RUN Powered by ADP. **Justworks** Basic requires 50+ EE, so it's unavailable.

At **25 employees**, the math shifts. **Gusto** Simple = $40 + (25 × $6) = $190/mo ($7.60/EE). **OnPay** = $40 + (25 × $6) = $190/mo ($7.60/EE) — same price, but Gusto includes the AI compliance bot and OnPay doesn't. **Paychex Flex Essentials** = $39 + (25 × $5) = $164/mo ($6.56/EE), still cheapest. **Rippling** Payroll = 25 × $8 = $200/mo ($8/EE) module-only, but realistically $400-600/mo with HR + Benefits modules. **ADP Workforce Now** would quote ~$200-350/mo ($8-14/EE). **Justworks** still unavailable.

At **100 employees**, you've outgrown the entry tiers. **Gusto** Plus is now the right SKU: $80 + (100 × $12) = $1,280/mo ($12.80/EE). **OnPay** stays at $40 + (100 × $6) = $640/mo ($6.40/EE) — half the cost of Gusto Plus, but you're giving up Plus's advanced reporting and SSO. **Paychex** moves you to Flex Select with custom pricing, typically $10-14/EE all-in. **Rippling** at 100 EE with full HR+Payroll+Benefits stack runs ~$25-35/EE, so $2,500-3,500/mo. **ADP Workforce Now** is competitive here at ~$1,200-1,800/mo ($12-18/EE). **Justworks** Basic = 100 × $59 = $5,900/mo ($59/EE) — five to ten times more than software-only options, because you're buying benefits leverage.

At **250 employees**, you're in mid-market territory. **Gusto** Premium kicks in (custom pricing, typically $15-22/EE). **OnPay** technically still works at $1,540/mo ($6.16/EE), but most 250-person companies want SSO, advanced reporting, and dedicated CSM — which OnPay doesn't ship. **Rippling**'s full stack runs $6,000-9,000/mo ($24-36/EE), but consolidates 4-6 other tools. **ADP Workforce Now** is the natural fit at this size: ~$3,000-5,000/mo ($12-20/EE) with the deepest compliance bench. **Paychex Flex Pro** quotes similar to ADP. **Justworks** Plus at $99/EE = $24,750/mo — wildly expensive on paper, but if you're getting 30% better group health rates than you'd get alone, it can still net positive.

The pattern: **OnPay** wins at every headcount on pure payroll cost. **Gusto** wins on UX and AI features for 1-100 EE. **Rippling** wins when you're consolidating 3+ tools. **ADP** and **Paychex** win at 100+ EE on compliance depth. **Justworks** wins when benefits leverage > software cost, which is almost always a 20-100 EE startup story. All prices verified as of June 2026 — verify at gusto.com/product/pricing, rippling.com/pricing, onpay.com/pricing, paychex.com/payroll/payroll-services-pricing, adp.com, and justworks.com/pricing before procurement.

One footgun: **Rippling**'s published $8/EE is for the Payroll module alone, paid annually. Month-to-month is higher. ADP and Paychex both negotiate aggressively — the published 'starting from' number is rarely the number you pay if you push back. Gusto, OnPay, and Justworks publish real prices that match what you'll actually pay.

Payroll doesn't live alone. It feeds accounting (QuickBooks, Xero, NetSuite), time tracking (Deputy, When I Work, Homebase), HR (BambooHR, Rippling, Workday), expense management (Brex, Ramp, Expensify), and benefits (Stripe, Justworks). Integration quality determines whether your finance close takes two days or two weeks. **Rippling** wins this category outright — 600+ native integrations plus a universal employee data API. Because Rippling owns the employee record, every integration is bi-directional and real-time. New hire in Rippling = laptop ordered, Slack provisioned, Salesforce seat assigned, 401(k) enrolled, all in one workflow.

**ADP Marketplace** has roughly 700 integrations, but they're built by partners against ADP's API, not native. Quality varies wildly. The QuickBooks Online sync is rock-solid; the Asana sync is a CSV export. **Gusto** ships ~200 native integrations covering the SMB stack — Xero, QuickBooks, Slack, Asana, Trainual, 15Five — and their API is clean. For a 50-person startup, Gusto's integrations are plenty. **Paychex** has 300+ via their Integrations Hub but the catalog is uneven; check for your specific tool before signing.

**OnPay** is the loser here. Roughly 25 integrations total — Xero, QuickBooks, Deputy, When I Work, Mineral HR, and a handful of 401(k) providers. No native API for custom builds, no Zapier integration of note. This is the trade for OnPay's flat pricing and simplicity: you don't get a platform, you get a payroll service. If you're using Notion as your HR system and Stripe for benefits, OnPay won't fit cleanly.

**Justworks** has ~50 integrations including Slack, Deel, and a developer API. Because Justworks is a PEO and owns the employer-of-record relationship, some integrations work differently — your 401(k) is Justworks' 401(k), not yours, which means you can't connect a third-party 401(k) admin. This is fine if you understand it going in and a nasty surprise if you don't.

Architecturally, **Rippling** is the only payroll vendor in this list that doesn't treat payroll as the system of record. Their unified employee graph means payroll, HR, IT, and Finance all pull from the same data. Every other vendor in the comparison treats payroll as the source of truth for employee data and forces HR/IT to sync to it. For a 50-person company this doesn't matter. For a 500-person company with 30 SaaS tools, it absolutely does.

If you want a deeper HRIS architecture comparison alongside payroll, our BambooHR vs Rippling vs Gusto comparison goes into the people-data layer specifically — which is often where you actually feel the integration pain.

Every payroll vendor claims 'full-service' tax filing. The differentiation is what happens when something goes wrong. **ADP Workforce Now** is the gold standard. ADP has a tax-research team of 200+ CPAs and former IRS agents. When you get a notice from a state department of revenue about a 2022 SUTA discrepancy, ADP handles it directly with the state, files the amended return, and pays any penalty if it was their error. Their Tax Filing Service is SOC 1 Type II audited and processes more US tax filings than any other private entity.

**Paychex** is a close second. Their compliance team is smaller than ADP's but equally credentialed, and Paychex has the same 'we handle the notice' guarantee. Both **ADP** and **Paychex** publish their Tax Penalty Guarantee terms publicly (see https://www.adp.com and https://www.paychex.com), which means if they file late or wrong, they pay the penalty. This is the single biggest reason to pay enterprise-tier pricing.

**Gusto** offers a Gusto Wallet tax guarantee for payroll-related penalties caused by Gusto error, documented in their TOS (https://gusto.com/terms). Coverage is solid but more limited than ADP/Paychex — Gusto won't represent you in an audit, they'll just refund the penalty. For a 1-100 EE company this is almost always enough. **OnPay** offers a similar guarantee; they file all federal, state, and local taxes and cover penalties caused by OnPay error (https://onpay.com).

**Rippling** files all taxes and offers a penalty guarantee, but their tax-research bench is smaller than ADP's and they're more likely to refer you to your CPA for edge cases. This is fine for most companies. It's not fine if you have employees in 30 states and you keep getting nexus questions wrong.

**Justworks**, as a PEO, files taxes under their EIN, not yours. This is structurally different — you're not filing 941s at all, Justworks is. This eliminates a whole class of payroll-tax compliance problems. It also means if you ever leave Justworks, you have to set up new tax accounts in every state where you have employees, which is a 60-90 day project. Plan for it.

The rule of thumb: at 1-50 EE, any of these vendors' tax filing is good enough. At 50-250 EE with multi-state employees, **Gusto** Plus, **Rippling**, **OnPay**, or **Paychex** all work — pick on UX and integrations. At 250+ EE with complex state and local tax exposure, **ADP Workforce Now** or **Paychex Flex Pro** are the defensible choices. Don't cheap out on compliance at scale.

Every vendor in this comparison is SOC 2 Type II compliant. The differentiation is what else they have. **ADP** holds SOC 1 Type II (financial reporting controls — important for public companies), SOC 2 Type II, ISO 27001, and various government-specific certifications including FedRAMP Moderate for ADP Government Solutions. If you're a public company, a government contractor, or a regulated industry, **ADP** is the only vendor in this list with the certification matrix to support your auditors without hand-waving.

**Rippling** holds SOC 1 Type II, SOC 2 Type II, ISO 27001, and ISO 27018. Their security posture is genuinely strong — they were founded by ex-Zenefits engineers who learned exactly how bad security incidents play out. Rippling also offers EU and UK data residency for Rippling Global customers, the only vendor in this comparison besides ADP with multi-region options.

**Gusto** is SOC 2 Type II and follows industry standard practices, but they're US-only on data residency and they don't carry the SOC 1 or ISO 27001 paperwork. For an SMB this is fine. For a 500-person fintech with EU employees, this is a blocker. **Paychex** matches Gusto's profile — SOC 2 Type II, US-focused, ISO certs available for higher tiers.

**OnPay** is SOC 2 Type II compliant per their security page. They're a smaller vendor with a focused product, so don't expect the certification matrix of an ADP. For their target customer (1-50 EE small business), this is the right scope of security investment. **Justworks** as a PEO is SOC 1 + SOC 2 Type II — they have to be, because they're holding payroll funds in their accounts.

Data residency is a sleeper issue. **Gusto**, **Paychex**, **OnPay**, and **Justworks** are US-only. **ADP** offers global payroll through ADP Global Payroll (separate SKU). **Rippling Global** offers EU/UK residency and international payroll in 50+ countries. If you have any EU employees, your only realistic choices in this comparison are **Rippling** or **ADP**.

Nobody in this list is self-hostable. Payroll requires tax-filing infrastructure (e-filing to IRS, state DORs, local jurisdictions) that you simply cannot replicate on-prem. If your security policy mandates self-hosting, payroll is not the system you self-host — pick a vendor with strong SOC 2 and move on.

**Founder, 1-5 employees, no benefits yet:** Pick **OnPay** at $40 + (5 × $6) = $70/mo per https://onpay.com/pricing. You get all-states filing, W-2s, 1099s, and zero surprise fees. The lack of AI features doesn't matter at this size. Alternative: **Gusto Simple** at the same $70/mo if you want the cleaner UX and AI compliance bot.

**Seed-stage startup, 10-30 employees, US-only, need group health:** Pick **Justworks Basic** at $59/EE — yes, it's expensive, but you'll get group health rates 20-40% better than you can negotiate alone, and Justworks handles workers' comp + EPLI. The PEO model also offloads compliance during the chaotic 20-50 EE phase where you don't yet have an HR person. Alternative: **Gusto Plus** at $80 + 30 × $12 = $440/mo if you've already got a benefits broker.

**Series A/B startup, 30-100 employees, consolidating tools:** Pick **Rippling**. The integrated HR+IT+Payroll story actually works at this stage — you're hiring fast, provisioning laptops and SaaS seats, and the unified workflow saves real hours per week. Yes, $25-35/EE all-in feels like a lot, but you're replacing 3-5 other tools. Source: https://www.rippling.com/pricing. Alternative: **Gusto Plus** + BambooHR if you want best-of-breed instead of platform.

**Established SMB, 50-200 employees, US-only, predictable headcount:** Pick **Paychex Flex** or **Gusto Plus**. Paychex if benefits are a big spend (they're a top-5 401(k) administrator); Gusto if UX matters more. Both will quote in the $10-14/EE range at 100 EE. Alternative: **ADP Workforce Now** if you have complex multi-state compliance.

**Mid-market company, 200-1,000 employees, multi-state:** Pick **ADP Workforce Now** or **Rippling**. ADP if you want compliance depth and your finance team already knows ADP. Rippling if you want unified IT+HR+Payroll and you have a CTO who wants one platform. Both will land $15-25/EE all-in. Don't pick **Gusto** at this scale — it works, but the reporting and SSO story falls behind.

**International company, EU/UK employees:** Pick **Rippling Global** or **ADP Global Payroll**. These are the only two vendors in this comparison with real international capability. Everyone else will tell you they 'integrate with' Deel or Remote, which means you're running two payroll systems. As of June 2026 — verify at rippling.com/pricing for current Rippling Global pricing, which is quote-only.

Pricing-page math is never the real bill. Expect implementation fees on the enterprise side: **ADP** and **Paychex** typically charge $500-3,000 for implementation depending on company size and module count. **Rippling** charges 1-2x the first month's bill as a one-time setup fee at most tiers. **Gusto**, **OnPay**, and **Justworks** do not charge implementation fees, which is real money on the table for SMBs.

Year-end forms are a classic gotcha. **ADP** and **Paychex** historically charged per-W-2 fees ($5-8 each) on top of monthly pricing. Both have largely moved this into base pricing in 2025-2026 but check your contract. **Gusto**, **OnPay**, **Rippling**, and **Justworks** include W-2/1099 generation in their flat per-EE pricing.

Off-cycle payroll runs (one-off bonuses, corrections, terminations mid-period) are free on **Gusto**, **Rippling**, **OnPay**, and **Justworks**. **ADP** and **Paychex** charge per off-cycle run ($25-75 typical, depending on contract). If you run more than 2-3 off-cycles per month, this adds up.

Multi-state filing is included on all vendors in this list. Local-tax filing (Ohio cities, Pennsylvania municipalities, NYC, San Francisco) is included on Gusto, Rippling, OnPay, ADP, and Paychex; Justworks handles it under their EIN. Don't pay extra for 'local tax' add-ons — if a vendor tries to charge you, push back.

The biggest hidden cost is platform consolidation. If you're currently running Gusto + BambooHR + Brex + Jamf + Okta + Carta and you move to Rippling, the apparent $30/EE Rippling bill replaces $80-120/EE across the existing stack. The reverse is true if you move OFF Rippling to point solutions — your itemized bill drops, but you spend 10-20 hours/week on integration glue.

Always model 24-month total cost, not month-one bill. As of June 2026 — verify at vendor pricing pages, especially ADP and Paychex where 'starting from' numbers are negotiating positions, not invoices.