Stratum PEO

Stratum PEO is an HR and payroll system for firms administering services for client organizations. It is best suited to PEOs, ASOs, staffing agencies, and CPA firms that need to run software on their own infrastructure. Its broad operational toolkit is balanced by the work of self-hosting and separately billed implementation and support.

Overview

Stratum brings payroll, client and employee administration, HR workflows, and CRM into a fully on-premises platform. That is a meaningful choice: organizations that need control over their own deployment may value it, while teams seeking a hosted service should look elsewhere. Its 16 FastAPI microservices sit behind one API gateway, with Next.js frontends; independent module deployment offers room to stage adoption, but does not remove infrastructure responsibilities.

Key features

Payroll and HR operations

An in-house tax engine handles federal, state, and local withholding in all 50 states and D.C., including multi-state allocation and NACHA ACH export. That makes the system relevant to service providers managing payroll across jurisdictions. Employee and client onboarding checklists include LLM-assisted I-9 extraction and E-Verify, while offboarding workflows cover separation notices in 21 states.

Client company portals, employee self-service, benefits enrollment, compliance tools, payroll and tax administration, and HR onboarding cover core service workflows. Case management adds SLA tracking, escalation rules, AI-assisted triage, and Twilio CTI call logging, alongside a sales CRM. Native connectors include BambooHR, Greenhouse, Lever, QuickBooks Online, Xero, Slack, Deputy, and Clockify. Migration adapters for ADP, Paychex, Gusto, Workday, Rippling, QuickBooks, and BambooHR may ease a move from those systems.

Security and compliance

Stratum describes schema-per-tenant PostgreSQL isolation, AES-256/Fernet encryption for PII at rest, bcrypt password hashing, mandatory MFA for privileged roles, SAML 2.0 SSO, and append-only audit logging. Those controls address important operational safeguards, but the company describes them as SOC 2 CC6-aligned and says a formal certification engagement is planned; buyers requiring completed SOC 2 certification should factor that distinction into evaluation.

Pricing

Annual pricing is divided by customer type and volume, with tier prices flat within each tier and reviewed at renewal. Temporary mid-cycle overages carry no retroactive billing or penalty, a useful buffer for short-lived growth, but renewal review still matters when forecasting ongoing costs.

CPA channel: Starter is $9,000 annually for up to 100 administered employees; Growth is $12,000 annually for 101–500; Established is $15,000 annually for 501–1,000. Established is capped and graduates to ASO pricing beyond that limit.

Staffing: Starter is $11,000 annually for up to 100 trailing-12-month placements; Growth is $14,000 annually for 101–500; Established is $18,000 annually for 501 or more placements.

ASO: Starter is $19,000 annually for up to 1,000 administered employees; Growth is $23,000 annually for 1,001–2,500; Established is $27,000 annually for 2,501 or more.

PEO: Starter is $25,000 annually for up to 1,000 covered employees.

The lower tiers suit smaller practices and operators, but their employee or placement caps define when a buyer must move up; the PEO Starter cap is based on covered employees, unlike ASO's administered-employee measure. Individual microservices can be purchased à la carte with pricing by contacting the company. Implementation and support cost $150/hr; break-fixes are covered by a 90-day warranty after signed go-live acceptance. That hourly cost makes rollout and ongoing assistance a separate budget consideration.

Platforms

Stratum supports Android, iOS, API, web, and self-hosted deployment. The self-hosted model is central rather than incidental: buyers need the infrastructure and operational capacity to run an on-premises system.

Who it's for

Stratum is aimed at PEOs, ASOs, domestic EORs, staffing agencies, and CPA firms running payroll for clients. Its workflow breadth and multi-state tax handling suit operators coordinating client and employee processes in one system. It is less suitable for organizations that want vendor-hosted deployment or need formal SOC 2 certification already in place.

Pros and cons

Pro: Multi-state tax handling, allocation, and ACH export address practical payroll needs across all 50 states and D.C.

Pro: Client and employee workflows, case management, CRM, and a wide set of native connectors bring several service operations together.

Pro: Independent module deployment and à-la-carte microservices allow a more selective rollout.

Con: Fully on-premises deployment puts infrastructure operation on the customer.

Con: Implementation and support at $150/hr can add substantial costs beyond the annual tier price.

Con: SOC 2 controls are described as aligned, with formal certification engagement still planned.

Alternatives

Consider PEO Software to compare the broader category. Choose Paychex PEO if a paid service with consultation-based custom pricing and company approval better fits your procurement process. PrismHR HCM Benefits Enrollment is worth considering when customizable, scalable options and benefits enrollment are the priority. VensureONE is another paid PEO option to evaluate. TriNet PEO Technology Platform may suit buyers seeking a customized estimate based on company size, industry, geography, and services. PEOAdmin is another paid alternative. For a per-active-worker option, PHRBO PEO Software charges $8 a month for Package 1, with no feature gates and a limit of 100 or fewer active workers. PRO Software uses quote-request pricing.

Verdict

Stratum PEO is a strong candidate for PEOs, ASOs, staffing firms, and CPA practices that want broad client-service workflows and multi-state payroll on infrastructure they control. Its main advantage is the combination of operational breadth and modular deployment; its chief drawback is the customer’s responsibility for self-hosting, compounded by hourly implementation and support. Choose it when that control is worth the operational and cost commitments, and look elsewhere if hosted delivery or completed SOC 2 certification is a requirement.