Office Administrator

Office Administrator (Part-Time)

Confidential Client – Design & Consulting Firm Industry

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

About the Opportunity

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.

Position Overview

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.

Key Responsibilities

Financial & Billing Operations

• Manage project-based invoicing across 100 active projects with varying billing structures and timelines
• Process invoices using internal systems (including BillQuick and QuickBooks)
• 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

Office Operations & Administration

• 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

Employee & HR Coordination

• 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

Client & Vendor Coordination

• 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

Project & Systems Support

• Maintain accurate records across multiple platforms (BillQuick, QuickBooks, Microsoft Office, etc.)
• Support project tracking, documentation, and reporting across various phases
• Assist with expense tracking and reimbursement processes tied to client projects

Qualifications

Required

• 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:
• QuickBooks
• 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

Preferred - Must Have

• Experience with BillQuick 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

Key Success Traits

• 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

Work Schedule & Compensation

• 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

Benefits & Perks

• 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

Why This Role

• 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