Corptax

Corptax makes tax provision and compliance software for large corporations, owned by CSC.

Corptax holds a large, sticky Fortune 500 base built on regulatory recognition and integration, but its next test is whether its own AI agents ship on time against ONESOURCE and CCH.

Corptax helps large companies calculate and file taxes across different countries using software that tracks rules by location and keeps detailed audit records. It is hard to replace because governments recognize its filings, companies' other software is locked into using it, and 50 years of data builds trust; but bigger companies like Thomson Reuters and Wolters Kluwer have more resources, and new AI tools that automate the routine work of sorting numbers and checking math could eventually make simpler versions of Corptax less necessary. The thing that matters most is whether Corptax can build its own AI tools fast enough to keep up with rivals while governments in Europe and beyond keep accepting its filing format as new tax rules roll out through 2026.

• About 1,000 corporate clients across roughly 100 countries (2026)
• Serves about 50% of the Fortune 500, per vendor claim (2026)
• Estimated revenue around $94 million with roughly 400 employees (2024)

• Mid-tier scale vs larger incumbents Thomson Reuters and Wolters Kluwer limits pricing power and market share. Severity: medium
• Generic agentic AI from competitors could commoditize lower-complexity provision and import/reconciliation work. Severity: medium
• CSC parent could deprioritize or divest the Corptax unit with no independent financial reporting to signal early warning. Severity: low
• Ongoing OECD Pillar Two rule changes across 60+ jurisdictions require continuous costly compliance updates. Severity: medium
• Financial and headcount data opacity makes independent verification of health difficult for customers and employees. Severity: low

Who owns Corptax?

Corptax is a business unit of CSC (Corporation Service Company), which is owned by WMB Holdings. CSC acquired Corptax in November 2011 by buying MLM Information Services from Warburg Pincus, after Deloitte Tax had sold the unit to MLM in 2006.

Is Corptax profitable?

Corptax does not disclose standalone financials; it operates as a unit of privately held CSC, which does not break out Corptax revenue or profit. Third-party revenue estimators disagree by 2 to 3x, so no reliable public profitability figure exists as of June 2026.

Could AI replace Corptax?

Unlikely soon. Corptax ships proprietary in-house AI agents (Import, Preparer, Reviewer, E-file) built by its own Head of AI, Dr. Ramsin Khoshabeh, announced 2025-09 to 2025-11, and holds HMRC-recognized Pillar Two filing status (June 2026), moats generic AI tools cannot easily replicate.

Who is Corptax's biggest competitor?

Thomson Reuters ONESOURCE is Corptax's closest rival in tax provision software, described as the category's provision leader; Wolters Kluwer (CCH) is a larger diversified tax-compliance incumbent also competing directly, as of 2026.

Has Corptax had layoffs?

No layoffs at Corptax have been publicly reported as of June 2026. Its parent CSC has continued unrelated acquisitions in adjacent compliance businesses, but no headcount reduction or divestiture signal specific to Corptax has surfaced.

Does Corptax support OECD Pillar Two global minimum tax filing?

Yes. As of June 2026, Corptax GMT supports direct electronic UK Pillar Two filing to HMRC via HMRC's Pillar 2 API, and Corptax tracks jurisdictional Pillar Two rules across more than 60 jurisdictions through its Eye on Pillar 2 hub.

• 2026-06-22Corptax GMT adds direct electronic UK Pillar Two filing to HMRC via HMRC Pillar 2 API
• 2026-05-03OECD Pillar Two Side-by-Side Safe Harbor administrative guidance becomes effective
• 2026-03-16Corptax publishes nVent customer testimonial on automated entity management
• 2025-11-12Corptax publishes fourth AI blog post, Corptax AI Powers the Future of Corporate Tax
• 2025-10-28Corptax publishes interview with Head of AI Dr. Ramsin Khoshabeh
• 2025-09-30Corptax publishes AI Tax Software: Smarter Data, Stronger Compliance blog
• 2025-09-22Corptax launches four-part AI blog series introducing Import, Preparer, Reviewer, E-file Agents
• 2025-01-08Corptax publishes GMT and GIR tax strategy roadmap post
• 2011-11-07CSC acquires MLM Information Services, including Corptax, from Warburg Pincus
• 2006-06-14Deloitte Tax sells Corptax business to MLM Information Services LLC

• Contact Details and Business Profile
• Deloitte Tax Sells Corptax Business (2006-06-14)
• CSC to Acquire MLM Information Services (2011-11-07)
• Corporation Service Company
• Corptax Tax Software for Corporations
• Management and Employees List
• Revenue, Competitors, Alternatives (2022-04-16)
• Corptax Software Revenue 2023 (2023-12-22)
• ASC 740 Tax Provision: ONESOURCE, Longview & NetSuite (2026-06-03)
• Corptax GMT Supports Direct UK Pillar 2 Filing Through HMRC (2026-06-22)
• The Future of Tax Tech: AI-Powered Tax Software (2025-09-22)
• Interview: Advancing Tax Tech with AI (2025-10-28)