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Redaction Use Cases

Bank statements are some of the most sensitive personal documents you hold. Here are the most common reasons to anonymise them before sharing.

Sharing Bank Statements with AI

AI assistants like ChatGPT, Claude, and Gemini are increasingly used to analyse financial data — categorising transactions, spotting patterns, or preparing summaries for tax returns.

The risk: uploading an unredacted statement sends your full account number, sort code, and transaction history to a third-party server.

The solution: anonymise the PDF first. Replace account numbers with placeholders, scramble names and addresses, and keep only the structural text the AI needs to understand the format.

Tips for AI sharing

  • Use the Always Anonymise table to replace your sort code and account number with safe placeholders (e.g., 00-00-00, 00000000).
  • Keep column headers in the Never Anonymise tab so the AI can parse the table structure.
  • If you need the AI to read transaction descriptions (e.g., for categorisation), enable Retain transaction descriptions — but review the output carefully before sharing.

Sending to Accountants and Bookkeepers

Your accountant needs to see your transactions to prepare accounts or a tax return. They don't need your full account details.

The risk: emailing unredacted statements exposes account numbers and personal details in transit and in the recipient's inbox.

The solution: produce an anonymised version that preserves the financial data while redacting personal identifiers.

Tips for professional sharing

  • Replace bank names in Always Anonymise if the professional doesn't need to know which bank the account is with.
  • Keep Never Anonymise entries for any text the accountant's software needs to parse (e.g., balance labels, transaction types).
  • Use batch mode to anonymise an entire year of statements in one go.

Bug Reports and GitHub Issues

openstan is open source, and bugs are reported on GitHub. When a statement fails to parse, the best way to get help is to attach the failing PDF — but you can't attach a real statement.

The risk: attaching an unredacted statement to a public GitHub issue exposes your financial data to anyone on the internet.

The solution: anonymise the PDF before attaching it. The parser can still read the structure, and developers can reproduce the issue without seeing your personal data.

Tips for bug reports

  • Use the Anonymise button directly from the Debug Info dialog (Import Results → click a REVIEW or FAILURE row). The tool opens pre-loaded with the failing statement's path.
  • Run the anonymisation, then verify the output still reproduces the bug before attaching it to the issue.
  • If the bug is in parsing logic, keep Never Anonymise entries for any text the parser depends on.

Compliance and Data Protection

GDPR, UK Data Protection Act 2018, and similar regulations require organisations to minimise personal data sharing. Bank statements contain multiple categories of personal data:

  • Account identifiers — account numbers, sort codes, card numbers
  • Transaction counterparties — merchant names, payee references
  • Financial details — balances, amounts, transaction descriptions
  • Personal information — names, addresses (on statements with letterhead)

The solution: anonymising statements before distribution is a practical way to meet data minimisation obligations while still sharing the financial information that's needed.

Compliance checklist

  • [ ] Replace all account identifiers with safe placeholders
  • [ ] Redact personal names and addresses
  • [ ] Review transaction descriptions for embedded personal data (e.g., payment references containing names)
  • [ ] Keep structural text intact for any downstream parsing
  • [ ] Document what redaction was applied and when

Internal Demos and Training

If you're demonstrating openstan or training colleagues, you need realistic-looking data without using real financial information.

The solution: anonymise a real statement to create a demo file that looks authentic but contains no personal data.

Tips for demos

  • Use Retain transaction descriptions to keep the data readable.
  • Add your own replacements in Always Anonymise to swap in fictional names or amounts.
  • Save the anonymised file as a reusable demo asset.

Next Steps