Accounts receivable Jobs in Antioch, CA

Mercor is hiring a Fractional Billing & AR Operations Specialist on behalf of a fast-growing AI research lab. This organisation partners with enterprises, research institutions, and venture-backed startups to deliver cutting-edge AI solutions. As the company scales, they are seeking an experienced billing and accounts receivable professional with a background in professional services environments (consulting, legal, advisory, or similar) . This role will bring structure, accuracy, and operational rigour to client billing, collections, and revenue tracking processes. This is an ideal opportunity for a detail-oriented finance operator who thrives in high-growth environments and can build scalable billing systems while maintaining strong client communication standards.

• Key Responsibilities ### Billing Operations - Own end-to-end client invoicing cycles, including time-and-materials, milestone-based, and retainer billing structures - Ensure accurate tracking of billable hours, project codes, and client-specific terms - Partner with internal stakeholders (finance, operations, client leads) to validate invoice inputs - Maintain clear documentation of billing policies and workflows ### Accounts Receivable (AR) Management - Monitor outstanding invoices and proactively manage collections - Lead professional, client-facing communication regarding billing inquiries and payment follow-ups - Maintain AR aging reports and provide visibility into cash flow forecasts - Identify patterns in payment delays and recommend process improvements ### Process & Systems Optimization - Assess and improve billing systems, tools, and reporting workflows - Implement scalable controls to support growth in client volume - Support monthly revenue reconciliation and financial reporting - Ensure compliance with contractual terms and internal financial controls * * * ## Requirements - 5+ years of experience in billing and AR operations - Prior experience in professional services environments (consulting firms, law firms, advisory practices, or similar) - Strong understanding of : - Time-based and project-based billing models - Revenue recognition fundamentals - AR aging and collections workflows - Experience working with accounting platforms (e.g., QuickBooks, NetSuite, Xero, or similar) - Excellent written communication skills for professional client correspondence - High attention to detail and strong process discipline - Ability to work independently in a fractional capacity * * * ## Preferred Qualifications - Experience supporting venture-backed startups or high-growth technology companies - Familiarity with SaaS or AI services billing structures - Experience building billing processes from early-stage or scaling environments - Background in financial reporting or FP&A collaboration * * * ## Why Join - Work at the forefront of AI innovation - Help operationalise finance infrastructure for a rapidly scaling AI lab - Flexible fractional engagement with meaningful ownership - Direct impact on revenue operations and cash flow strategy