Stratum PEO

Stratum PEO is an HR and payroll platform for PEOs, ASOs, domestic EORs, staffing agencies, and CPA firms that administer payroll for clients. It runs fully on-premises on the customer’s own infrastructure. Its architecture uses 16 FastAPI microservices behind one API gateway, with Next.js frontends and independently deployable modules. The in-house tax engine handles federal, state, and local withholding across all 50 states and D.C., multi-state allocation, and NACHA ACH export. HR workflows include onboarding checklists with assisted I-9 extraction and E-Verify, plus separation notice workflows covering 21 states. The platform also includes case management, SLA tracking, escalation rules, AI-assisted case triage, call logging, and sales CRM. Native connectors include BambooHR, Greenhouse, Lever, QuickBooks Online, Xero, Slack, Deputy, and Clockify. Annual plans include CPA, staffing, ASO, and PEO options, from $9,000 a year for CPA channel Starter to $27,000 a year for ASO Established. Implementation and support are listed at $150/hr.

Stratum PEO combines client payroll, HR workflows, CRM, and integrations in an on-premises platform. Annual plan pricing varies by service type and tier, and implementation and support are listed separately at $150/hr.

Stratum PEO is intended for organizations that administer payroll for clients, including PEOs, ASOs, domestic EORs, staffing agencies, and CPA firms. Its on-premises deployment suits customers seeking to run the platform on their own infrastructure.

Stratum PEO is a self-hosted HR and payroll platform for organizations administering services for clients. It is best suited to PEOs, ASOs, staffing agencies, and CPA firms that want control over their own deployment. Its broad operational scope is balanced by annual tier costs and the responsibility of running it on customer infrastructure.

Overview

Stratum brings payroll, HR workflows, client administration, and CRM into one platform for service providers. Customers deploy it fully on-premises, so it is a stronger fit for organizations that need to operate software in their own environment than for teams seeking a hosted service with little infrastructure ownership.

Its architecture consists of 16 FastAPI microservices behind a single API gateway, with Next.js frontends; modules can be deployed independently. That modular design supports selective rollout, but does not remove the operational burden of maintaining the customer-run environment.

Key features

Payroll, HR, and client service

The in-house tax engine handles federal, state, and local withholding across all 50 states and D.C., with multi-state allocation and NACHA ACH export. This is a useful foundation for providers serving clients with workers across jurisdictions. Onboarding checklists cover employees and clients, including LLM-assisted I-9 extraction and E-Verify. Offboarding includes separation-notice workflows covering 21 states, a narrower reach than the tax engine's nationwide scope.

Client company portals, employee self-service, payroll and tax administration, benefits enrollment, compliance tools, and HR onboarding cover central service workflows. Case management adds SLA tracking, escalation rules, AI-assisted triage, and Twilio CTI call logging; a sales CRM is also included. Together, these capabilities make Stratum more relevant to firms coordinating service across client accounts than to a single employer looking only for payroll.

Integrations and security

Native connectors include BambooHR, Greenhouse, Lever, QuickBooks Online, Xero, Slack, Deputy, and Clockify. Migration adapters cover ADP, Paychex, Gusto, Workday, Rippling, QuickBooks, and BambooHR, which can help firms move from established systems or connect adjacent tools. The platform describes schema-per-tenant PostgreSQL isolation, encryption of PII at rest, bcrypt password hashing, mandatory MFA for privileged roles, SAML 2.0 SSO, and append-only audit logging. Its controls are described as SOC 2 CC6-aligned; formal certification is planned, not stated as complete.

Pricing

Stratum is paid software with no free plan. Annual plan pricing varies by service type and capacity:

Each tier's price is flat within its stated capacity, with review at renewal. Temporary mid-cycle overages do not trigger retroactive billing or a penalty, which gives operators some room for short-term volume swings. CPA Established is explicitly capped and transitions to ASO pricing beyond its employee limit. Individual microservices can be purchased à la carte with custom pricing. Implementation and support cost $150/hr; break-fixes are covered by a 90-day warranty after signed go-live acceptance. These costs and the on-premises deployment make Stratum a less natural fit for buyers seeking a low-commitment or fully managed starting point.

Platforms

Stratum supports Android, iOS, web, API, and self-hosted deployment. The self-hosted model is central to the product rather than an optional alternative to a hosted service.

Who it's for

Stratum is aimed at PEOs, ASOs, domestic EORs, staffing agencies, and CPA firms running payroll for clients. Its service-specific tiers let CPA channel, staffing, ASO, and PEO operators select capacity around different measures, while the portals and CRM support ongoing client operations. Firms without the infrastructure resources or appetite to manage an on-premises system should look elsewhere.

Pros and cons

• Pros: One platform spans payroll, HR workflows, client portals, benefits enrollment, compliance tools, and CRM, reducing the need to treat those service functions as wholly separate systems.
• Pros: Nationwide tax withholding coverage, multi-state allocation, and ACH export suit payroll providers handling geographically distributed workforces.
• Pros: Independent microservice deployment and à la carte modules allow a more selective rollout than an all-or-nothing package.
• Cons: Customers must run the platform on their own infrastructure, adding an operational responsibility that hosted-service buyers can avoid.
• Cons: Annual tiers start at $9,000 a year, while implementation and support are charged separately at $150/hr.
• Cons: SOC 2 CC6 alignment is not the same as completed formal certification; organizations requiring an existing certification should account for that distinction.

Alternatives

Consider PEO Software for a broader comparison of options. PrismHR HCM Benefits Enrollment is worth considering when customizable, scalable options and Android, iOS, and web access matter; its pricing is custom. VensureONE is another paid option for Android, iOS, and web. TriNet PEO Technology Platform may suit buyers seeking a customized estimate based on company size, industry, geographic footprint, and needed services, with Android, iOS, web, and API support. Paychex PEO is an alternative for companies seeking tailored services through a consultation and approval process, with support for Android, iOS, macOS, Windows, and web. PEOAdmin is another paid option. PRO Software is a paid, web-based option priced by quote request.

Verdict

Stratum PEO is a strong candidate for client-service firms that want payroll, HR workflows, and CRM under one roof and are prepared to operate software on their own infrastructure. Nationwide payroll coverage and modular deployment are its clearest advantages. Choose another product if hosted delivery or completed SOC 2 certification is a must, or if the annual commitment and hourly support costs do not fit the budget.