Corptax

Corptax (acquired by CSC) is the fiercely aggressive, highly entrenched titan locked in an absolute, perpetual war with ONESOURCE for dominance over the Fortune 500 tax department. While ONESOURCE built a massive ecosystem of distinct modules, Corptax's entire architectural philosophy is "The Single System of Record." They mathematically fused the Tax Provision and the Tax Return into a single, terrifyingly robust database, completely eliminating data reconciliation errors. Its signature feature is "The Mathematical Blueprint." In Corptax, a tax professional builds a mathematical map of the entire corporate structure (e.g., Parent Company -> Sub A -> Sub B). When the trial balance is loaded, the data mathematically flows through this blueprint. The exact same data point (e.g., 'Depreciation Expense') is simultaneously used to calculate the SEC Tax Provision and the IRS 1120 Corporate Tax Return automatically, without a human ever copying and pasting the number. It heavily dominates "US Consolidated Federal and State Returns." Calculating tax for a company that operates in all 50 US states is an absolute mathematical nightmare due to complex state apportionment rules (how much revenue belongs to California vs. Texas). Corptax mathematically ingests the sales, payroll, and property data, and automatically calculates the exact apportionment percentage for every single state, instantly generating 50 perfectly compliant state tax returns.