ADP vs Paychex is a comparison of two sales quotes. Neither company publishes a price for any payroll package, so any site that names a cheaper one is guessing. What you can compare is the paperwork. For a business under 50 employees, ADP RUN’s public terms are easier to live with: 30 days’ notice to leave and no one-year lock-in on its promo. Paychex is the better pick if its written quote is lower, or if you have 50 to 250 employees and want its promo.
ADP vs Paychex pricing: two “request a quote” buttons
Every package on ADP’s RUN page and its Workforce Now comparison shows “Get pricing”. All six packages on Paychex’s compare page, from Basic through HR PEO, show “Request Pricing”. We found no “starting at” figure on either site.
ADP says RUN quotes depend on worker count, worker type, pay frequency, payment method and support level (ADP). Paychex doesn’t publish its pricing inputs, but its compare page offers self, assisted or managed setup and online, enhanced or premium support. Expect those choices to change the quote.
Third-party price estimates exist for both, and we don’t use them here. One Paychex estimate refers to package names Paychex has since retired, and one ADP estimate conflicts with its own source’s “custom pricing” label. A guessed price winner would be worse than none.
Tier lineups and employee-count bands
This is how the two lineups line up by company size, based on each vendor’s own pages:
| Need | ADP | Paychex |
|---|---|---|
| Small-business payroll | RUN, “best fit” for 1–49 employees: Essential, Enhanced, Complete Payroll & HR+, HR Pro | Paychex Flex: Basic, Foundations (“Best Value”), Advanced, Complete |
| Midsize and larger | Workforce Now, for 50+: Select, Plus, Premium | “Midsize to Large Businesses” page; Paycor acquired April 2025 |
| HR help without a PEO | RUN Complete and HR Pro add HR support | Paychex HR Pro: HR guidance, safety/OSHA, 401(k), payroll |
| PEO (co-employment) | ADP TotalSource, 5 to 1,000+ employees | Paychex HR PEO |
Sources: ADP RUN vs Workforce Now, ADP TotalSource, Paychex compare, Paychex enterprise, Paycor acquisition.
There are two differences in how the two sites present this.
- ADP maps features to packages. Paychex doesn’t. The RUN page shows what each package adds: SUI service and garnishment payment service from Enhanced up, and HR support from Complete up. Paychex’s compare page lists features such as time and attendance, job costing, applicant tracking and an LMS without saying which tier includes each. You need the rep to tell you, in writing.
- ADP’s size bands are consistent. Paychex’s aren’t. ADP draws the line at 50. On the day we checked, Paychex’s navigation used 20–99 and 100+ bands while its footer used 20–49 and 50–100+ (Paychex). This doesn’t change what you buy, but don’t rely on the band labels to tell you which product you’ll be quoted.
The fine print is the real comparison
Paychex: the promo comes with a one-year agreement
Paychex’s current offer, “Do Not Pay Until April 2027”, gives new clients with 1 to 250 employees up to six free months of payroll. The promo runs from October 12 to October 31, 2026, unless Paychex extends it (Paychex). The terms are what matter:
- It requires “a one-year service agreement” that “includes a termination clause.”
- It covers “the payroll component only”. Setup, NSF, delivery, premium processing, 401(k), time and attendance and other one-time fees are still billed. None of those amounts are published.
- Leave before one year and Paychex may “recover the value of any free months provided”, in addition to other early-termination recovery.
In our view, the clawback turns a discount into a commitment. If there’s a real chance you’ll switch within 12 months, value the promo at zero.
ADP RUN: easy to leave, but the price can move
ADP’s RUN Terms and Conditions (effective February 12, 2026) are public, which is already more than Paychex offers for standard Flex accounts. The key clauses:
- Either party can terminate “on at least thirty (30) days prior written notice” (§12A). Outstanding fees fall due on termination (§12B).
- After a new client’s first six months, ADP may raise base processing fees with at least 30 days’ notice (§4A).
- A maintenance fee applies to any 30-day period with no payroll processed, except for digital self-purchasers. The amount isn’t published (§4A).
- Late amounts accrue 1.5% interest a month (§4A).
ADP’s promo, up to six free months for new RUN clients with 1 to 49 employees who sign by November 26, 2026, has no one-year agreement in its offer terms. It does have strings attached. You must stay three consecutive months on the same bundle, and credits post in months 4 to 6 and 13 to 15, so collecting the full value takes 15 months. Off-cycle, delivery, hardware and penalty fees are excluded. Essential clients who sign up digitally get three months, not six.
Standard terms: one is public, one isn’t
For the account you’ll actually have after any promo, ADP publishes its RUN terms. Paychex’s standard, non-promo Flex service agreement isn’t public, so we can’t tell you its notice period or termination fees. Your signed order or Sales Order can change things with either vendor, but with Paychex you start from nothing you can read in advance. Ask for the agreement before the demo ends.
ADP TotalSource vs Paychex PEO
If you’re considering a PEO, the contract stakes are higher, because the PEO files payroll taxes under its own EIN rather than yours (Paychex).
- ADP TotalSource is listed on the ADP Marketplace as an IRS-certified PEO (CPEO) and ESAC-accredited. It serves U.S. businesses with 5 to over 1,000 employees and covers HR, benefits, payroll and tax, workers’ comp and safety (ADP Marketplace). We haven’t reviewed a TotalSource client agreement, so we can’t compare its exit terms.
- Paychex HR PEO publishes its PEO terms (effective October 7, 2026). The initial term, renewal and your notice period are set in a Signature Packet, and Paychex may terminate on 30 days’ notice. Leaving triggers a transition fee based on employee count, waived only if you give the required notice. Leaving early adds an early termination fee: terminated employee count times a per-day amount times the days left in the term. Paychex also charges $5 per full-time employee per month if it administers health and welfare plan deductions.
On accreditation, ESAC’s directory shows Paychex as accredited since 2015. In a 2017 press release, Paychex announced IRS certification for subsidiaries of its PEO arm. Check the current status of both on the IRS CPEO list before signing, because certification can be suspended or revoked.
For a 20-person business, the Paychex early-termination formula is the number to get in writing. Ask for the per-day amount and the length of the initial term, and work out the worst case before you sign.
Ratings and complaints, attributed
- ADP RUN. Rated 4.6 out of 5 on Capterra (1,577 reviews). The BBB lists 871 complaints in three years, 207 in the past 12 months. Recurring themes are billing after cancellation and tax-filing errors. Capterra reviewers say add-ons push the total up.
- Paychex Flex. Rated 4.2 on Capterra (1,820 reviews), with customer service at 3.9. Reviewers mention frequent rep reassignment and prices rising over time. Trustpilot shows 1.7 out of 5 from 869 reviews, many describing slow cancellations and charges afterward. The BBB rates Paychex A+, with 573 complaints in three years.
The pattern is similar for both: billing after cancellation shows up in both companies’ complaints. Whichever you choose, cancel in writing and keep the confirmation.
Paychex vs ADP: a decision framework
There’s no reliable price winner, so we pick by situation:
- Under 50 employees and you want to know the exit terms in advance: quote ADP RUN first. Its terms are public and the promo carries no clawback.
- 50 to 250 employees: Paychex’s promo covers you. ADP’s doesn’t, and you’d be quoted Workforce Now. Get both quotes, and price in the one-year agreement.
- You want a PEO now or soon: quote TotalSource and Paychex HR PEO together. Compare initial term, notice period, transition fee and early-termination formula. Don’t compare monthly fees alone.
- Seasonal payroll: ask ADP for the idle-month maintenance fee in writing. Ask Paychex whether its agreement has any minimum or idle charge.
- You might switch within 12 months: avoid the Paychex promo, or negotiate the clawback out.
- You want to see prices before talking to sales: neither fits. Start with ADP alternatives or our Gusto vs ADP comparison, which works through published prices.
How to make two quotes comparable
Ask both vendors for these, in writing:
- Package name, base fee and per-employee fee at your headcount and pay frequency.
- Setup fee, per-delivery fee, off-cycle fee, W-2 or year-end fee and garnishment fee.
- Term length, renewal and notice period, plus any early-termination charge.
- When and how the price can rise after the first year (or, for ADP, after month 6).
- For promos: the exact months credited and what happens if you leave.
Add up 12 months of each and compare annual totals. Our guide to switching payroll providers covers timing the move, and our methodology explains how we verify terms.
Bottom line
Choose ADP vs Paychex on the contract, not on a price you can’t see. ADP RUN is the safer default under 50 employees because you can read its terms before you sign. Paychex is a reasonable pick if its written quote is lower for the same features, or if you’re between 50 and 250 employees and its promo applies. In that case, the one-year agreement and the clawback are part of the price.