Part-Time Payroll, Accounts Payable, and Office Administration

Polymer; San Leandro (CA); On-site; USD 34,000 - 48,000; Part time

Job summary

PHNX Materials is seeking a part-time Payroll & Office Administrator to handle payroll processing and office operations on-site in California. The role requires meticulous attention to detail, strong organization, and the ability to coordinate payments, invoices, and vendor services.

You will maintain payroll records in QuickBooks, route documents correctly, and ensure deadlines are met while keeping sensitive information confidential.

Qualifications

• Experience with payroll and payroll processing
• Ability to review payroll reports for discrepancies
• Strong attention to detail and accuracy
• Ability to work independently with part‑time schedule

Responsibilities

• Process payroll accurately and on time, verify time records and changes
• Review payroll reports and obtain required approvals
• Maintain QuickBooks entries and confidential records
• Process and pay vendor invoices with approvals
• Manage internal Payroll and Benefits system
• Prepare and submit invoices to third parties for payment
• Receive, log, and route incoming checks, bills, and mail
• Coordinate janitorial services and office supplies
• Route questions to appropriate person and ensure resolution
• Escalate missing information and deadlines to prevent issues
• Maintain checklists so recurring tasks are reliable

Skills

Payroll processing

Vendor payments

Invoicing accuracy

Office administration

Attention to detail

Tools

QuickBooks

Job description

This is a part-time role, 20-25 hours per week, with one flexible day per week on site.

About PHNX

PHNX Materials is the world’s first solids’ refinery company. We extract 30+ critical metals from industrial waste while selling 100% of the input feed as co-products. We are unlocking America's domestic supply of critical minerals.

About the Role

PHNX Materials is seeking a part-time Payroll & Office Administrator to manage payroll and keep essential office operations running smoothly. You’ll own accurate, timely payroll processing, maintain records in QuickBooks, coordinate office services, and ensure incoming checks, bills, and requests reach the right people. This role requires exceptional attention to detail, sound judgment, and consistent follow-through. You’ll work 20-25 hours per week, including one day in the office each week; the on‑site day is flexible, with availability around payroll deadlines required.

What You’ll Do

• Process payroll accurately and on time, verifying time records, pay rates, deductions, and employee changes before submission

• Review payroll reports, resolve discrepancies, and obtain required approvals before processing

• Maintain accurate QuickBooks entries and organized, confidential payroll and financial records

• Process and pay vendor invoices with appropriate approvals, tracking due dates and payment confirmations

• Manage internal Payroll and Benefits management system

• Prepare and submit invoices to third parties for payment, maintain supporting documentation, and follow up on outstanding balances

• Receive, log, and route incoming checks, bills, and mail

• Coordinate janitorial services, office supplies, and other routine office needs

• Route questions and documents to the appropriate person and follow through until resolved

• Escalate missing information, discrepancies, and time‑sensitive issues early enough to prevent missed deadlines

• Maintain clear checklists and records so recurring tasks are completed reliably

What We’re Looking For

• Hands‑on experience with payroll, QuickBooks, vendor payments, and submitting invoices to third parties for payment

• Exceptional attention to detail, with a demonstrated record of payroll accuracy and careful verification

• Strong organization, discretion, and follow‑through; sound judgment about routing information and escalating issues

• Ability to work independently within a part‑time schedule, meet payroll deadlines, and work on site one flexible day per week

Nice to Have

• Experience supporting a manufacturing, industrial, or plant‑based business

• Experience coordinating janitorial services and other office vendors

• Comfort with spreadsheets and improving administrative checklists and processes

• Experience working with an external accountant, bookkeeper, or payroll provider