Accounts Payable Specialist

Commonwealth Fusion Systems is on a mission to deliver the urgent transition to fusion energy. Combining decades of research, top talent, and new technologies, we’re designing and building commercially viable fusion power plants. And we're working with policymakers, suppliers, and many others to build the energy industry of the future.

We’re in the best position to make it happen. Since 2018, we’ve raised $4 billion of capital, making us the largest and leading fusion company in the world.

Now we’re looking for more thinkers, doers, builders, and makers to join us. People who’ll bring new perspectives, solve tough problems, and thrive as part of a team.

If that’s you and this role fits, we want to hear from you.

As an Accounts Payable Specialist, you will be responsible for providing accurate, timely accounts payable processing while helping improve how invoices move from receipt to payment. Reporting to the Accounts Payable Supervisor, the AP Specialist will manage a high-volume invoice queue, investigate discrepancies, coordinate resolution with vendors and internal partners, and support month-end close. The role calls for curiosity about why problems occur and practical ideas that reduce repeat issues, delays, and rework.

The AP Supervisor remains accountable for team priorities, oversight, and escalation decisions. The AP Specialist owns assigned invoice processing, documentation, and follow-through; coordinates with the responsible buyer, requester, or approver; and escalates unresolved issues with facts and a proposed next step. Payment approvals, purchasing decisions, and accounting policy remain with authorized owners.

• Invoice processing: Manage roughly 200–300 invoices per week; verify vendor, invoice number, date, amount, entity, PO, and coding using approved guidance; investigate duplicate alerts before processing
• Matching and controls: Perform two-way and three-way matching; verify receipts, service approvals, payment terms, tax, freight, and exemption support; resolve or elevate discrepancies before payment
• Exception resolution: Work with Procurement, Receiving, requesters, and vendors to resolve missing receipts, insufficient PO funds, billing errors, and approval delays; track hold reasons, owners, and next action dates
• Vendor and payment support: Respond professionally to payment inquiries; obtain corrected invoices and credit memos; track credits and refunds; prepare payment support under established approvals and safeguards, including duplicate-payment checks for automatic debits
• Month-end support: Identify unbilled vendor and contractor costs; provide accrual support and reconcile vendor statements and AP records; coordinate coding questions and close items with Accounting
• Process improvement: Identify recurring exceptions and their causes; recommend practical fixes; update procedures and support approved workflow improvements, system testing, and cross-training
• Own the follow-through: Organize the queue by due date and risk, follow up promptly, and close the loop with vendors and internal partners
• Ask and investigate: Question unclear or inconsistent information, use supporting records to understand the issue, and bring recommendations to the supervisor
• Collaborate and protect controls: Work constructively across functions, communicate blockers early, handle sensitive information carefully, and preserve required approvals and documentation

• Relevant high-volume accounts payable experience, including two-way and three-way matching, vendor communication, and month-end support
• ERP experience required
• Working knowledge of debits and credits, accruals,…