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ADP RUN Powered by ADP vs Paychex Flex

ADP RUN Powered by ADP5.1/10

Paychex Flex7.2/10

Scored in Payroll Software

The short answer

RUN Powered by ADP sells four packages, from Essential Payroll to HR Pro Payroll & HR, by quote. Paychex Flex publishes one entry price, Flex Essentials at $39 a month plus $5 per employee for businesses with fewer than 20 workers, and quotes its Basic to Complete packages.

By LeadChange Research TeamUpdated Based on 17 sources, most recently checked

ADP RUN Powered by ADP

Best for
Small businesses paying 1 to 49 employees, including owners who pay only themselves

Choose ADP RUN Powered by ADP if

  • You want to run payroll by phone call as well as online or in the app.
  • You want legal assistance and a learning management system in the top package (HR Pro).
  • You export the general ledger to Wave or Creative Solutions as well as QuickBooks or Xero.
  • You want recurring payroll to run on its own.

ADP RUN Powered by ADP plans and pricesADP RUN alternatives

Paychex Flex

Starting price
$39/mo + $5/employee/mo (up to 19 employees)1
Best for
Businesses with fewer than 20 employees that want a listed price

Choose Paychex Flex if

  • You have fewer than 20 employees and want a published price: $39 a month plus $5 per employee.
  • You run extra or off-cycle payrolls: Paychex Flex includes unlimited payroll processing.
  • You want employees to review their own paychecks before payroll runs (Paychex Pre-check).
  • You need a REST API with webhooks.

What Paychex Flex costsPaychex Flex alternatives

LeadChange Score: editorial assessment based on public information.

Scorecard

ADP RUN Powered by ADP wins 0Paychex Flex wins 12 ties

ADP RUN Powered by ADP vs Paychex Flex by dimension
DimensionADP RUN Powered by ADPPaychex Flex
PricingPaychex Flex lists Flex Essentials at $39 a month plus $5 per employee; its other packages are quoted, and tax administration, W-2s and 1099s may cost extra on Essentials. ADP RUN quotes every package and charges more as payroll frequency rises. Paychex Promise (delay the payroll debit up to 7 days): free for the first 3 months, then $99 per year, Payroll tax administration and W-2s and 1099s on Flex Essentials: "additional fees may apply" for tax administration; W-2s and 1099s at additional cost, Set-up and support upgrades (Assisted or Managed Set Up, Enhanced or Premium Customer Support) cost extra on the packages that do not include them, Add-ons available for all packages, no price published: Time & Attendance, HR Analytics, Talent Management, Business Insurance, Retirement Plans, Health Insurance, Workers’ Comp, HR Consulting2Quote only$39/mo + $5/employee/mo (up to 19 employees)
CapabilitiesBoth cover payroll, tax filing, contractor payments, HR tools and add-on benefits. ADP RUN adds bill pay and invoicing and applicant tracking by CareerPlug; Paychex Flex adds time and attendance and workers' compensation modules. Payroll, Payroll tax filing, Contractor payments, HR support (HR HelpDesk), Recruiting (ZipRecruiter; applicant tracking by CareerPlug in HR Pro), New hire onboarding, Learning management (HR Pro), Garnishment payment service, State Unemployment Insurance management, Bill pay and invoicing, Time and attendance (add-on)310 of 12 core capabilities12 of 12 core capabilities
Fit and supportADP RUN offers 24/7 payroll support by phone or chat; Paychex lists 24/7 payroll support, with a payroll specialist on its Complete package. 24/7 payroll support by phone or chat3Small businessesSmall businesses, mid-market companies

ADP RUN Powered by ADP or Paychex Flex: what matters most to you?

We match on verified product facts for this need, never on who pays us.

Key differences

Where ADP RUN Powered by ADP and Paychex Flex differ (8)
AttributeADP RUN Powered by ADPPaychex Flex
Pricing modelQuote only3Base fee + per employee1
Price transparencyQuote only3Partly published4
Best forSmall businesses5Small businesses, mid-market companies6
Mobile appsRUN Powered by ADP app (iOS), RUN Powered by ADP app (Android)7Paychex Flex app (iOS), Paychex Flex app (Android), Paychex Flex Time Kiosk app8
Support channelsPhone, chat, email, HR HelpDesk by phone and email (Complete and HR Pro)9Phone, chat, email, in-platform help center10
Typical implementationSome customers are up and running within 2 days; others transition over a period of weeks9Self-guided online setup; first payroll as soon as the same day11
Founded19495197112
HeadquartersRoseland, NJ, US5Rochester, New York and Cincinnati, Ohio, US (dual headquarters)6
Show 6 attributes where they are the same
Where they are the same (6)
AttributeADP RUN Powered by ADPPaychex Flex
Minimum employees113111
DeploymentCloud, mobile3Cloud, mobile6
API1415
Automatic tax filing310
Contractor payments310
OwnershipPublicly traded5Publicly traded6

Analysis by dimension

Pricing. Paychex Flex lists Flex Essentials at $39 a month plus $5 per employee; its other packages are quoted, and tax administration, W-2s and 1099s may cost extra on Essentials. ADP RUN quotes every package and charges more as payroll frequency rises.

Capabilities. Both cover payroll, tax filing, contractor payments, HR tools and add-on benefits. ADP RUN adds bill pay and invoicing and applicant tracking by CareerPlug; Paychex Flex adds time and attendance and workers' compensation modules.

Integrations. Paychex Flex offers a REST API with webhooks and lists QuickBooks, Sage Intacct, Xero, NetSuite, When I Work and 7shifts among its integrations. ADP RUN connects to QuickBooks, Xero, Wave, Creative Solutions, Clover and ZipRecruiter.

Fit and support. ADP RUN offers 24/7 payroll support by phone or chat; Paychex lists 24/7 payroll support, with a payroll specialist on its Complete package.

Security. Neither names a security certification on the product pages we reviewed.

Neither one?

Patriot Payroll

Patriot Payroll has the highest LeadChange Score in Payroll Software after excluding these two (8.7/10).

From $37/mo + $5/employee/mo (Full Service Payroll plan)16

Patriot Payroll review

Frequently asked questions

Who is cheaper, ADP or Paychex?

Only Paychex publishes a price: Flex Essentials costs $39 a month plus $5 per employee, or $89 a month for 10 employees, before tax administration and year-end forms. ADP quotes RUN, so compare written quotes for the same headcount and pay frequency.

Does Paychex Flex charge for extra payroll runs?

No. Paychex Flex includes unlimited payroll processing with no additional fees. ADP RUN does not include unlimited runs: its payroll fees increase with payroll frequency.

Do ADP RUN and Paychex Flex check payroll with AI?

Yes. ADP Assist flags payroll errors before payroll runs and imports timesheets; Paychex’s WISE flags missing punches, pay rates and direct deposit approvals before payroll runs and suggests fixes.

How quickly can I start with ADP RUN or Paychex Flex?

Paychex Flex offers self-guided online setup with a first payroll as soon as the same day. ADP says some RUN customers are running within 2 days and others move over a few weeks.

Do ADP RUN and Paychex Flex offer health insurance and 401(k)?

Both sell them as add-ons. ADP RUN offers group health insurance, retirement plans through ADP Retirement Services and workers' compensation; Paychex Flex offers 401(k) plans, group health insurance and a free perks marketplace for employees.

Where are ADP and Paychex based?

ADP, founded in 1949, is headquartered in Roseland, New Jersey. Paychex, founded in 1971, has dual headquarters in Rochester, New York and Cincinnati, Ohio.

Is ADP RUN Powered by ADP or Paychex Flex more secure?

ADP RUN Powered by ADP states GDPR (unverified for Paychex Flex).

How this page was made

  • What it is built from

    38 verified facts, each checked against the vendor's own pages or another primary source, most recently on Nov 8, 2026.

  • Method

    Scored and compared with the LeadChange methodology, version 1.5. Read the methodology

  • Independent review

    Not reviewed yet by our independent reviewer. How we review

  • Hands-on testing

    We have not tested either product hands-on: this page uses public information only.

  • Who made it

    The LeadChange Research Team, following a written research process. No named expert has reviewed this page. About us

  • Independence and errors

    Who pays us never changes a score or a rank. If something here is wrong, tell us and we correct it publicly. Request a correction

ADP RUN Powered by ADP or Paychex Flex? Your answer in 3 questions

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ADP RUN Powered by ADP vs Paychex Flex

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Sources

The 17 pages this page's facts come from, with the day we last checked each one. The numbers beside the figures above link here.

Quotes from the sources
  1. Paychex paychex.com/payroll/paychex-flex-essentials“Our most affordable option: Only $39/mo. + $5 per employee”
  2. Paychex paychex.com/paychex-promise“Paychex Promise is free for the first three months of service. After the initial 3-month period, the annual subscription is $99 per year.”
  3. ADP adp.com/what-we-offer/payroll/payroll-for-1-49-employees/payroll-packages.aspx“Applicant Tracking System, powered by CareerPlug … Learning Management System … Garnishment Payment Service … State Unemployment Insurance (SUI) Management … Bill Pay and Client Invoicing … Time and Attendance” “24/7 Customer Support Get answers to your payroll questions any time of day over the phone or by online chat from experienced payroll professionals.”
  4. Paychex paychex.com/payroll/compare-payroll-solutions“Basic Essential Payroll & HR Request Pricing Foundations AI & HR Features Best Value Request Pricing Advanced Enhanced Service Needs Request Pricing Complete Premium Services Request Pricing”
  5. ADP sec.gov/Archives/edgar/data/8670/000000867026000030/adp-20260630.htm“RUN Powered by ADP®, serving over 980,000 small businesses, is an all-in-one platform designed specifically for small businesses to simplify payroll, HR, and compliance.” “In 1949, our founders established ADP with a simple, innovative idea: help clients focus on their business by solving their payroll challenges.”
  6. U.S. SEC (Paychex Form 10-K, fiscal 2026) sec.gov/Archives/edgar/data/723531/000119312526307785/payx-20260531.htm“Paychex Flex® is our proprietary HCM SaaS platform for small and medium-sized businesses. Paycor® is our primary SaaS-based HCM platform for larger businesses with more complex needs.” “maintains dual corporate headquarters in Rochester, New York and Cincinnati, Ohio”
  7. ADP (Apple App Store listing) apps.apple.com/us/app/adp-run/id388928133“the RUN Powered by ADP® payroll mobile app is built for the way your small business works. Here are some of the features available at your fingertips—wherever your day takes you. • Start payroll with a tap • Avoid payroll mistakes with error detection powered by AI”
  8. Paychex paychex.com/apps/mobile-app“Employees can download the Paychex Flex® app for free from the Apple App Store or Google Play Store and log in using their Paychex account credentials.”
  9. ADP adp.com/what-we-offer/payroll/payroll-for-1-49-employees/switching-to-adp.aspx“Support from a payroll specialist via phone & email, at no additional fee … ADP offers 24/7 access to real payroll professionals to help resolve issues before they impact your team or business.” “With ADP, some customers can be up and running within 2 days, while others choose to transition over a few weeks.”
  10. Paychex paychex.com/payroll“Have any questions? We offer flexible support options via phone, chat, or email to help you when you need it.” “We automatically calculate, file, and pay your payroll taxes for you.”
  11. Paychex paychex.com/payroll/one-employee-payroll“Sign up from mobile or desktop and follow a self-guided, simple, step-by-step process to run your first payroll as soon as today.” “Payroll Services for One Employee Running your business on your own is no small feat – running payroll shouldn’t make it harder.”
  12. Paychex paychex.com/corporate“Paychex was founded in 1971 with an insight by B. Thomas Golisano.”
  13. ADP adp.com/what-we-offer/payroll/payroll-for-one-employee.aspx“Fast, simple payroll for one employee ADP for One is payroll built for S corps and solopreneurs, from the small business payroll pros at ADP.”
  14. ADP marketplace-cdn.adp.com/dev-portal/pdf/protected/RUN_Powered_by_ADP_API_Catalog“The Marketplace API Catalog for RUN Powered By ADP lists APIs supported by RUN Powered By ADP”
  15. Paychex paychex.com/integrations“Plus, Paychex APIs and developer resources make building applications, connections, and solution integrations easier than ever.”
  16. Patriot Software patriotsoftware.com/pricing“Basic Payroll is $17/month + $4 per worker paid; Full Service Payroll is $37/month + $5 per worker paid.”
  17. ADP adp.com/privacy.aspx“ADP has adopted Binding Corporate Rules (BCR) for processing Client employee data and business contact data.”

What the LeadChange Score means

A 0–10 editorial assessment built only from verified facts, across six weighted dimensions: capabilities, pricing, integrations, security, fit and support, and data confidence.

Payments, commissions and lead fees are never inputs.