Tax Manager/Senior Tax Manager
Old Mission
| Company | Old Mission |
| Category | Finance |
| Location | Chicago |
| Remote | On-site (inferred) |
| Employment | Not stated |
| Level | Manager |
| Salary | Not stated by the employer |
| Posted | 2 Jul 2026 |
| Last verified | 12 Aug 2026 |
| Source | Employer ATS (greenhouse) |
Description
Old Mission is a global proprietary trading firm that leverages state-of-the-art technology and research to identify and execute profitable trading strategies across multiple asset classes around the world. Our offices in Chicago, New York, and London are all composed of naturally-curious individuals who thrive in a team environment and constantly strive for improvement.
Old Mission does not seek capital from outside investors, allowing us the flexibility to aggressively invest in our team members and keep them engaged in the firm’s growth. About the position
This is a hands-on role in every sense. The Tax Manager works alongside the Tax Director, not behind them. Both positions are expected to work together: preparing workpapers, reviewing returns, conducting primary research, owning compliance deadlines, and building the analysis that informs the firm’s tax positions.
Responsibilities
U.S. International Tax
Prepare and own U.S. international tax compliance workpapers and supporting schedules across the firm's controlled foreign corporations and partnerships, including GILTI/NCTI, FDII/FDDEI, BEAT, Subpart F, foreign tax credits and FTC limitation analysis, and foreign withholding and treaty positions
Maintain and update CFC and partnership analyses including tested income, tested loss, net deemed tangible income return calculations, and high-tax exclusion evaluations; coordinate with external advisors on FTC planning and transfer pricing strategies
Monitor the impact of OBBBA, evolving IRS guidance, and OECD Pillar Two developments on the firm's international tax positions and assess implications for compliance and planning
Support transfer pricing documentation and intercompany agreements for cross-border transactions between U.S. and foreign entities.
Federal, State & Local Tax Compliance
Prepare tax return information packages and detailed workpapers for external tax consulting firms; independently review all externally prepared federal and state returns prior to submission
Support preparation and review of indirect tax filings including VAT, Use Tax, and GST across applicable domestic and international jurisdictions
Own withholding and information reporting obligations for Forms 1099, 1042-S, and 8804 for the firm and its related entities
Build and maintain the firm’s tax compliance calendar; proactively identify all upcoming deadlines and coordinate timely completion with internal teams and outside advisors
Research, Planning & Authority Response
Conduct primary research on federal, state and local, and international tax issues; prepare well-reasoned technical memos for Tax Director review
Prepare substantive responses to information document requests (IDRs) from the IRS, state, and city taxing authorities; maintain organized examination support files
Monitor and assess legislative and regulatory developments including IRS guidance, Treasury regulations, and OECD Pillar Two updates; brief the Tax Director on implications for the firm
Provide tax analysis in support of proposed transactions, new entity structures, and strategic initiatives
Process, Data & Technology
Identify and implement process improvements to tax workflows; evaluate new tools and procedures for more accurate, efficient compliance
Leverage Excel (Power Query, XLOOKUP, PivotTables, array formulas) and AI research tools to streamline workpaper preparation, data manipulation, and reconciliation
Document and maintain policies, procedures, and internal controls for the Tax function
Work cross-functionally with Accounting, Legal, and Operations on tax