bareminimum

For tax advisers · reviewed 2026-11-01

Claude for tax advisers, with client data replaced

PESEL, NIP, REGON, IBAN, names and addresses in your prompts reach Anthropic as consistent stand-ins of the same kind, and come back restored in Claude's reply.

Your duty

Art. 37 of the Act on tax advisory (ustawa o doradztwie podatkowym) obliges you to keep secret the facts and information you learn in your profession. Since resolution 40/2026 of 13 April 2026, art. 8a of the KRDP code of ethics adds that, using IT systems and AI tools, a tax adviser must ensure the confidentiality of client data and verify their results before using them.

What bareminimum does about it

  • Identifiers are replaced by look-alikes that pass the same checksum: a NIP stays a valid NIP of the same tax office, so Claude's reasoning about it still holds.
  • Names decline as the originals do, so a draft letter reads right when it comes back.
  • Detection runs inside the gateway; no third-party service reads your text to find personal data.

What stays yours

  • Verifying Claude's results, which art. 8a(b) asks of you; the gateway changes no figures.
  • Amounts, company names and the facts of a matter reach Anthropic as written.
  • Scans and PDFs are refused, not read: paste the text instead.

Check it yourself · What Anthropic still sees · All questions