Construction Financial Assistant

Southborough, MA | Full-Time | Monday–Friday (In-Office)

One Source Construction LLC is a Massachusetts-based general contractor specializing in public and commercial projects. We operate in a fast-paced, compliance-driven environment where accuracy, documentation, and accountability are critical.

We are building a highly structured, process-driven accounting operation to support our continued growth. This role is critical to maintaining financial accuracy, supporting project profitability, and ensuring compliance across all projects.

This role is not transactional. You will be expected to actively manage financial processes, identify discrepancies, and ensure that billing, job costing, and documentation are accurate and complete.

We are looking for someone who does not wait to be told what’s wrong—but takes initiative to identify and resolve issues.

We are seeking a detail-oriented and process-driven Financial Assistant to support our construction accounting operations. This role is responsible for accounts payable, accounts receivable, job cost tracking, billing support, and maintaining audit-ready financial records.

You will work closely with project managers and leadership, directly impacting billing accuracy, job costing, and financial visibility across projects.

• Prepare and initiate AIA/progress billings by proactively coordinating with Project Managers and field teams
• Drive the billing process forward by gathering required information, following up with PM/APM teams, and ensuring billing is completed accurately and on time
• Review, prepare, and process accounts payable with full supporting documentation
• Coordinate with Project Managers and field teams to verify invoices, job cost coding, and approvals
• Ensure vendor payments are accurate, properly coded, and processed on time
• Proactively follow up on missing invoices, approvals, or documentation to ensure accounts payable is processed without delays
• Identify discrepancies in job costing, billing, or records and resolve them proactively
• Support overall cash flow management by ensuring timely billing and accurate, well-coordinated vendor payments
• Reconcile company credit cards and track receipts
• Maintain accurate records in QuickBooks Desktop (Contractor Edition)
• Track subcontractor compliance (COIs, documentation)
• Maintain organized, audit-ready job and accounting files
• Maintain logs for financial tracking

• Billing is accurate, timely, and complete
• Job costs are properly coded and reliable for decision-making
• Financial records are consistently audit-ready
• Issues are identified early and resolved without escalation
  

• This role is responsible for initiating and driving the billing process—not waiting for information to be provided. Strong follow-up and coordination with project teams is required to ensure timely and accurate billing.
• This role requires proactive follow-up and coordination across teams. Responsibilities include initiating billing processes and ensuring accounts payable is completed accurately and on time—without waiting for direction.
• Tasks are not considered complete until fully documented, reconciled, and verified
• Strong organizational discipline is required
• Ability to follow structured processes and checklists
• Comfortable working in a deadline-driven, detail-heavy environment
  

• 3+ years of bookkeeping/accounting experience in construction
• Experience with:
• AIA / progress billing
• Construction AP/AR
• Job cost accounting
• Proficiency in:
• QuickBooks Desktop (Contractor Edition)
• Microsoft Excel, Outlook, Word
• Adobe Acrobat
• Strong attention to detail and organizational discipline
• Ability to work full-time in-office

• Public/municipal construction experience
• Procore experience
• Notary Public (or willing to obtain)
  

• $70,000 – $80,000 (based on experience)
• Performance-based bonus
• Health, Dental, Vision
• 401(k) with company match
• PTO and paid holidays

The pay range for this role is:

70,000.00 - 80,000.00 USD per year (Southborough Office)