Check

Check at a Glance

Important audience note. If you are an employer comparing payroll for your own business, Check is not what you are shopping for. Check sells to product teams at SaaS companies offering native payroll to their customers. End-employer buyers should evaluate Gusto, OnPay, QuickBooks Payroll, or Rippling. The rest is written for platform builders evaluating embedded payroll infrastructure.

Pros and Cons of Check

Who Should Use Check

Check is a platform-infrastructure decision, not an end-user payroll decision. The buyer is a product, engineering, or partnerships leader at a SaaS company who has decided native payroll is strategic enough to own.

Vertical SaaS platforms whose customers run payroll. Restaurant-tech (7shifts, Dripos), home services (Housecall Pro), construction (Trayd, Miter), childcare (Playground), and auto-retail (Tekion) all run on Check. The platform already owns scheduling or operations, and payroll is the natural next product. Without Check, the platform either refers customers out and loses the workflow, or spends three-plus years building tax-filing infrastructure in-house.

Workforce-management and HRIS platforms going downmarket on payroll. Platforms such as Eddy and Homebase added native payroll on Check because SMB customers would not pay for both a workforce app and a separate Gusto subscription. Check lets the platform fold payroll into one bill and one login.

Accounting and bookkeeping platforms. Wave Payroll is the canonical example. Accounting platforms with SMB distribution use Check to ship payroll as a paid module. Payroll attach rates typically run 30 to 50 percent of the active accounting base.

POS and operations platforms with payroll-adjacent data. Tekion (auto dealerships), Dripos (coffee shops), and similar platforms already capture hours, tips, and roles. Layering native payroll on Check turns a sticky operational tool into a revenue-multiplier product.

Not the right fit: Employers running their own payroll (use Gusto, OnPay, Paychex Flex, or ADP Run), platforms with fewer than 1,000 prospective payroll-paying customers (engineering cost outweighs revenue), platforms whose customers are predominantly outside the US, and platforms that want a white-label resale relationship rather than an API build.

Check Product Suite

Check sells one product, the embedded payroll API. The surface covers five functional areas; partners pick the depth they expose and Check handles the regulated portions.

Wage and Net-Pay Calculation Engine

The core API takes hours, rates, bonuses, tips, and deductions and returns gross wages, withholdings, FICA, FUTA, SUTA, and net pay. Multi-state and tipped-employee scenarios are handled out of the box.

Tax Filing in 50 States plus DC

Check files federal Form 941, Form 940, state withholding, state unemployment, and applicable local taxes on the partner's behalf. The Money Transmitter License and SOC 2 Type II posture enable this. For platforms, this is the highest-value piece of the API because replicating it in-house requires both a license footprint and a dedicated compliance team.

Money Movement and Direct Deposit

ACH and same-day ACH disbursement to employees, contractors, and tax authorities. Check handles bank-account verification, NACHA compliance, returns, and reversals. Partners route money into Check's licensed entity and Check moves it onward.

Tax Forms and Year-End

W-2 and W-3 for employees, 1099-NEC and 1096 for contractors, plus state-specific year-end forms. The API returns PDF and structured data so platforms can deliver forms inside their own product.

Compliance and Risk Operations

Check operates the compliance, fraud, and risk back office. KYB on new employer accounts, fraud monitoring on funding events, and remediation when filings are rejected. Partners get an in-house compliance team without staffing one.

How Much Does Check Cost

Model total cost as three variables: per-active-employee monthly fee, per-pay-run transaction fee, and any minimum commitment. Public case studies suggest Check's economics work when the partner can charge 30 to 60 USD per month plus 5 to 10 USD per employee at retail (consistent with Gusto and OnPay). Below that band, partner margin is thin.

Implementation Plan: Rolling Out Check

Check implementations are engineering-heavy, multi-month efforts. Plan a 90-to-180-day build from contract signature to GA launch.

Weeks 1 to 4: Contract and sandbox access. Sign the master services agreement and data processing agreement. Complete Check's KYC and platform-due-diligence questionnaire. Get sandbox API credentials, review the OpenAPI spec, and run first integration tests against synthetic records. Most platforms staff this with two engineers, a product manager, and a compliance reviewer.

Weeks 5 to 12: Core integration build. Wire up employer onboarding (company info, tax IDs, bank verification), employee onboarding (W-4, I-9, direct deposit), pay-run creation, and reporting endpoints. Build the partner-side UX in your own product and pipe data to Check. Plan two to three iteration cycles with Check's solutions engineering before UAT.

Weeks 13 to 18: UAT and pilot customers. Onboard 5 to 25 friendly pilot employers across multiple states. Run parallel payroll cycles for two pay periods to verify wage calculations and tax filings match expectations. Resolve state-specific edge cases (tipped wages, remote workers, garnishments).

Weeks 19 to 24: General availability. Open the product to the broader customer base in waves. Track payroll-attach rates against existing accounts, monitor first-pay-run completion rates, and review filing-rejection rates weekly. Most partners hit a stable run-state by month six.

Hidden Costs and Contract Gotchas

Engineering opportunity cost dwarfs Check's fees. The 90-to-180-day build typically consumes two to four full-time engineers plus product and design support. Budget the loaded labor cost (often 150,000 to 400,000 USD in fully-burdened time) on top of Check's platform fees when modeling year-one TCO.

Minimum-volume commitments. Partnership contracts frequently include processing-volume or active-employee minimums. If your customer base does not adopt payroll as quickly as forecast, the minimums still apply. Negotiate ramp curves explicitly.

Support boundary is shared, not handed off. Tier-one questions (paycheck math, deductions, deposit timing) land in your queue. Staff a payroll-trained support pod before launch; do not assume Check handles end-customer email.

US-only coverage is a hard ceiling. Check does not file or move money outside the US. International expansion requires a second vendor (Deel, Remote, or similar) which doubles the number of integrations to maintain.

Brand and trust transfer. When Check has a filing or money-movement issue, your customers experience it as your problem. Review the SLA and incident-communication clauses carefully before signing.

What Real Buyers Report

Positive themes from public partner case studies include the depth of the API surface (most platforms ship a credible payroll product on Check in under six months versus three-plus years in-house), the Money Transmitter License footprint as a regulatory moat, the responsiveness of Check's solutions-engineering team during integration, and the named-partner roster (Eddy, 7shifts, Homebase, Housecall Pro) that signals production-proven scale.

Critical themes include the engineering-heavy integration, the lack of public pricing, support-boundary ambiguity during the first 60 days post-launch, and the US-only scope which forces a second-vendor decision for international ambitions. Partners on developer forums noted that the build is justifiable only with clear payroll-attach data showing material revenue lift.

Check Alternatives

Bottom Line

Check is the category-defining embedded payroll API, not an SMB payroll product. For SaaS platforms whose customers run US payroll and where native payroll attaches meaningful revenue, the regulatory moat (SOC 2 Type II, Money Transmitter License in 50 states plus DC), the named-partner depth, and the production-proven scale (1 million+ employees paid, 15 billion USD+ processed) make Check the safest infrastructure choice available. Trade-offs are engineering-heavy integration, opaque sales-led pricing, US-only coverage, and the commitment of operating a regulated financial product. Employer-side buyers comparing SMB payroll should evaluate Gusto, OnPay, or Patriot Software; the broader market lives in the payroll software guide and the adjacent HR software directory.