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Administrative Assistant- Irvine, CA

Trinet Group

Irvine, CA · Posted September 29, 2026

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About the job

TriNet is a leading provider of comprehensive human resources solutions for small to midsize businesses (SMBs). We enhance business productivity by enabling our clients to outsource their HR function to one strategic partner and allowing them to focus on operating and growing their core businesses. Our full-service HR solutions include features such as payroll processing, human capital consulting, employment law compliance and employee benefits, including health insurance, retirement plans and workers’ compensation insurance.

TriNet has a nationwide presence and an experienced executive team. Our stock is publicly traded on the NYSE under the ticker symbol TNET. If you’re passionate about innovation and making an impact on the large SMB market, come join us as we power our clients’ business success with extraordinary HR.

Don't meet every single requirement? Studies have shown that many potential applicants discourage themselves from applying to jobs unless they meet every single requirement. TriNet always strives to hire the most qualified candidate for a particular role, ensuring we deliver outstanding results for our small and medium-size customers. So, if you're excited about this role but your past experience doesn't align perfectly with every single qualification in the job description, nobody’s perfect – and we encourage you to apply. You may just be the right candidate for this or other roles.

A Brief Overview The Administrative Assistant (AA) will be responsible for utilizing AI to execute high-volume, standardized administrative tasks with accuracy and efficiency and o perate within a metrics-driven model that tracks response times, completion rates, and service quality . The AA will be on a team providing centralized support in service of all leaders / departments at TriNet, gaining broad organizational knowledge and cross-functional expertise , with a s tructured development pathway to become a strategic EA through training, mentorship, and exposure to leadership

What you will do

Expense Report Management: Process, reconcile, and submit expense reports using TriNet's expense management systems

Travel Coordination: Book domestic and international travel including flights, hotels, ground transportation as directed, provide complete itineraries and add to leader calendars

Purchasing & Procurement: Execute purchasing requests and manage purchase card reconciliation

Distribution Lists Management: Create, maintain, and update email distribution lists across departments and leadership teams

Reporting & Documentation: Generate routine reports, maintain documentation, and ensure accurate record-keeping for administrative processes

Be knowledgeable and help communicate policy changes to Corporate Administration team

Utilize AI in every aspect of work

Assist in creation of SOPs, intranet page.

Coordinates travel and special projects as requested

General administrative work: Heavy calendaring, purchasing within policy guidelines using a department Purchase Card, including expense validation, updating, and creating department process documentation within a central repository, event planning (dinners, happy hours, etc.)

Act as point of contact in TriNet’s Irvine location for administrative professionals and workplace services in relation to various office visit protocols to ensure compliance with TriNet policies

Proactively manage outstanding action items to ensure responsiveness and follow through on commitments / asks

Interact extensively with administrative professionals within the Corporate Administration team as well as within other departments/organizations

Assists management with administrative tasks including preparing various reports detailing administrative information.

Other projects and responsibilities may be added at the manager’s discretion.

Performs other duties as assigned

Complies with all policies and standards

Education Qualifications

Associate’s degree preferred

Experience Qualifications

Typically requires general education, vocational training and/or on-the-job training, plus a minimum of 2 - 4 years of related experience.

Skills and Abilities

Leads with a customer service approach and highly organized manner

Sense of urgency to accomplish tasks, both assigned and self-discovered

High level of discretionary judgment and confidentiality

Identify opportunities for process simplification and efficiency improvements

Maintain high attention to detail and accuracy in all work

Excellent verbal and written communication skills as well as the ability to communicate with colleagues at all levels within the organization

A demonstrated dedication to high professional ethical standards and a diverse workplace

Proficient in Microsoft Office Suite including Teams OneDrive and One Note

Ability to adapt to a fast paced continually changing business and work environment while managing multiple priorities

A keen interest in how our business is run, and a thirst to learn every day

Travel Requirements Minimal

Work Environment

Work in a clean, pleasant, and comfortable office work setting. The work environment characteristics described here are representative of those an employee encounters while performing the essential functions of this job. Reasonable accommodations may be made to enable persons with disabilities to perform the essential functions.

The preferred location for this role is Irvine, CA, and the salary range for this location is $29.76 to $44.62. All qualified external applicants will be considered for an in-office role, based in Irvine. All qualified internal candidates are encouraged to apply and consider relocation to Irvine and may be considered remote hire at the company’s discretion. The candidate’s final salary offer will be based on the candidate’s skills, education, work location and experience.

A candidate’s compensation may also include bonuses consistent with TriNet’s corporate bonus plan.

Additionally, subject to applicable eligibility requirements, TriNet offers permanent full-time employees a variety of benefits including medical, dental, and vision plans, life and disability insurance, a 401(K) savings plan, an employee stock purchase plan, eleven (11) Company observed holidays, PTO and a comprehensive leave program. Please click the following link for detailed information about our benefits offerings: https://www.trinet.com/documents/blt5b61a1040aae1904

Please Note: TriNet reserves the right to change or modify job duties and assignments at any time. The above job description is not all encompassing. Position functions and qualifications may vary depending on business necessity.

TriNet is an Equal Opportunity Employer and does not discriminate against applicants based on race, religion, color, disability, medical condition, legally protected genetic information, national origin, gender, sexual orientation, marital status, gender identity or expression, sex (including pregnancy, childbirth or related medical conditions), age, veteran status or other legally protected characteristics. Any applicant with a mental or physical disability who requires an accommodation during the application process should contact recruiting@trinet.com to request such an accommodation.