Thomson Reuters ONESOURCE

Thomson Reuters ONESOURCE is a modular corporate tax platform for mid-sized accounting firms and in-house tax departments that covers income tax provision, indirect tax calculation, transfer pricing documentation, and country-by-country reporting in a single environment.

The indirect tax module handles sales and use tax, VAT, and GST rate determination and works alongside major ERP systems. The income tax provision tool automates ASC 740 and IFRS calculations and produces the disclosures needed for audit. A workflow layer tracks due dates, assigns tasks to team members, and keeps sign-off trails for each return.

ONESOURCE connects with SAP, Oracle, and NetSuite via pre-built connectors, and an open API supports custom integrations. The platform targets mid-market to enterprise entities and the accounting firms that handle their tax compliance, not solo practitioners or small bookkeeping shops.

Firms handling multi-entity clients can run provision calculations across dozens of subsidiaries in a single batch rather than opening separate workbooks for each entity. The indirect tax engine applies the correct rate at the transaction level, so your team is not maintaining rate tables manually.

The strongest use case is a firm whose clients operate across multiple jurisdictions and need consistent indirect tax rates applied at the transaction level inside SAP or Oracle. Firms with simpler domestic-only clients will find most of the platform's depth unnecessary and the sales-led pricing hard to justify against lighter alternatives like Avalara or TaxDome.

Pricing is entirely sales-led. Thomson Reuters does not publish a price list for ONESOURCE. Firms contact the sales team to scope modules and licensing based on entity count, jurisdictions, and the number of users.