Tax research answers you can trace back to the source.

C9 AI reads your tax documents and reference material, answers your question, and shows the exact document and page behind every figure. Built for CPAs, bookkeepers, payroll specialists and people filing their own taxes.

Add your sources

Upload slips, returns, statements, guides and emails, or save a public web page to your Library.

Ask in plain language

Ask the question the way you would ask a colleague. No special search syntax needed.

Check the evidence

Every answer cites the document and page it came from, so you can verify before you rely on it.

Why cited answers matter in tax work

A tax answer is only useful if you can defend it. C9 AI keeps the source attached, labels whether it came from a client file or your shared Library, and keeps each client's documents in a separate workspace.

Answers cite the document and page, and actions appear in an audit trail.
Documents are stored privately and their text is encrypted.
A shared Library holds guides and reference material every workspace can use.