Office Administrator

Location: Irvine, CA (Onsite – Hybrid Office Environment MWF)

A well-established, boutique design and consulting firm is seeking a detail-oriented and proactive Office Administrator to support day-to-day operations, financial administration, and client coordination.

This is a high-impact, hands-on role supporting a collaborative team of professionals across multiple active projects. The organization operates in a project-based, professional services environment (similar to architecture, engineering, and interior design firms), where billing, invoicing, and client coordination require a high degree of accuracy and organization.

This role is ideal for someone who thrives in a dynamic, fast-paced environment, enjoys working independently, and takes pride in keeping operations running smoothly.

The Office Administrator will be responsible for managing core office operations, financial processes, and administrative functions, with a strong emphasis on project-based invoicing, bookkeeping, and coordination across multiple stakeholders.

This individual will serve as a central point of coordination across leadership, employees, clients, and vendors, ensuring that administrative, financial, and operational workflows are executed efficiently.

• Manage project-based invoicing across 100+ active projects with varying billing structures and timelines
• Process invoices using internal systems (including Bill Quick and Quick Books)
• Track project phases, billing percentages, and client-specific invoicing requirements
• Record and reconcile incoming payments, including check deposits and system updates
• Support payroll coordination and basic bookkeeping functions

• Oversee daily office operations including mail, supplies, and general organization
• Maintain office systems and ensure operational continuity in a hybrid work environment
• Coordinate internal processes, documentation, and administrative workflows
• Support leadership with scheduling, reporting, and operational needs

• Assist with employee benefits administration (PTO tracking, insurance coordination, 401k support)
• Provide general personnel coordination and administrative support
• Help onboard new employees and support internal communications
• Serve as a professional and responsive point of contact for clients and vendors
• Manage communications related to billing, documentation, and project coordination
• Ensure all client interactions reflect a high level of professionalism and service

• Support project tracking, documentation, and reporting across various phases
• Assist with expense tracking and reimbursement processes tied to client projects

• 3–5+ years of experience in an Office Administrator, Office Manager, or similar role
• Experience in project-based, professional services environments (architecture, engineering, interior design, consulting preferred)
• Strong experience with:
• Quick Books
• Project-based billing/invoicing
• Highly detail-oriented and organized with the ability to manage multiple priorities
• Strong written and verbal communication skills with a client-first mindset
• Ability to work independently in a hybrid/low-occupancy office environment

• Experience with Bill Quick or similar time & billing platforms
• Familiarity with Bluebeam or industry-specific tools
• Exposure to payroll systems (e.g., ADP)
• Experience supporting multi-entity or project-driven businesses

• Extremely detail-oriented (critical for project billing accuracy)
• Proactive and solution-oriented
• Strong interpersonal and client communication skills
• Positive, team-oriented mindset (“make a friend” culture)
• High level of accountability and ownership

• Part-Time:
  Approximately 20–30 hours per week
• Schedule:
  
  Typically, 3 days onsite (flexible structure)
• Compensation:
  Competitive hourly rate (commensurate with experience; market-aligned)
• Pay
  
  Schedule:
  
  Semi-monthly
• Paid Time Off (PTO) and sick leave
• Paid holidays, including extended holiday time during the Christmas/New Year period
• Eligibility for medical benefits (based on hours worked and tenure)
• 401(k) eligibility (based on service requirements)
• Collaborative, team-oriented environment with strong tenure and client relationships

• Opportunity to play a critical role in a growing, highly respected firm
• High visibility with leadership and direct impact on operations
• Exposure to complex, project-based business operations
• Stable organization with long-standing client relationships and strong reputation