TriNet (Zenefits)

TriNet (which acquired Zenefits) is a professional employer organization (PEO) that provides payroll, benefits, compliance, and HR administration services for small and medium businesses. As a PEO, TriNet co-employs a client’s workforce and takes responsibility for payroll tax filings, benefits procurement, and regulatory compliance.

Accounting firms working with SMB clients on TriNet coordinate with the platform to access payroll records, tax filings, and benefits cost data needed for financial reporting and tax preparation. The PEO model bundles these services, giving firms a single source for employment-related financial data.

TriNet is best suited for small to mid-sized businesses (5–500 employees) that want outsourced HR administration and access to group-rate benefits. Like Justworks, the PEO model is not appropriate for every business — firms should evaluate whether clients need the benefits access and compliance support that a PEO provides versus a standalone payroll platform.