Founded in 1983 by principal shareholder William I. Koch, Oxbow Carbon LLC ("Oxbow") is a global leader in recycling, marketing, and upgrading of refinery and natural gas coproducts. Oxbow produces and distributes calcined and fuel grade petroleum coke and provides bulk storage and handling services for petroleum coke and other commodities. Leveraging its extensive scale, strong expertise, and leading market positions, Oxbow has established a powerful global sourcing platform supported by superior market intelligence and long-standing relationships with key suppliers and customers. Oxbow's products are essential in the production of aluminum, steel, glass, and cement, while its specialty offerings are integral to a variety of innovative applications, including high-performance plastics, solar panels, electronics, and batteries. Oxbow's continued success and leadership within the industry are attributed to a combination of strong teamwork, innovative uses of technology, and talented employees. The Tax Manager is responsible for managing the Company's U.S. tax compliance activities, including federal and state corporate income tax returns, partnership tax returns, sales and use tax compliance, and other miscellaneous filings. This role will oversee the timely and accurate preparation, review, and filing of tax returns, coordinate with external advisors, support tax audits, and provide tax guidance to internal stakeholders. The ideal candidate will possess strong technical tax knowledge, excellent project management skills, and experience supervising tax compliance processes across multiple jurisdictions. Essential Duties and Responsibilities Manage the preparation, review, and filing of federal, state, and local corporate income tax returns.

Manage the preparation and review of partnership tax returns, Schedules K-1, and related filings.

Oversee U.S. sales and use tax compliance, including return preparation, review, remittance, and nexus analysis.

Coordinate with external tax advisors and service providers to ensure complete and accurate tax filings.

Review tax workpapers, supporting documentation, and tax calculations prepared by internal staff or external advisors.

Monitor tax filing deadlines and maintain an effective tax compliance calendar.

Support federal, state, and local tax audits, examinations, and information requests.

Research and analyze tax law changes and communicate the impact to management and relevant business functions.

Assist with tax accounting, including provision support and related tax reconciliations.

Identify opportunities for process improvements, automation, and enhanced internal controls within the tax function.

Partner with accounting, finance, legal, treasury, and operational personnel on tax-related matters.

Assist with special projects, tax planning initiatives, and strategic business transactions as assigned.