Redacting client documents in-house, a guide for law and finance firms

Every week, a law or finance team sends documents outside the firm: statements to an auditor, contracts to the other side, KYC packs to a bank, case bundles to a court. Most of them need something removed first. A client's account numbers, a counterparty's address, an employee's ID, a file path in the footer that names the client.

Doing that well is harder than it looks, and doing it with the wrong tool quietly creates the risk it was meant to remove.

Why "just use an online tool" doesn't work for client files

Free online redaction tools are quick, but they work by uploading the unredacted original to someone else's servers. Most say they delete files within one to two hours. For your own payslip that may be fine. For a client's documents, it often isn't:

• Engagement terms and client agreements frequently limit where client data may be sent.
• Internal policies may require that confidential files stay inside the firm's network.
• Data protection law applies wherever you work, whether that's the GDPR in Europe and the UK, state privacy laws and sector rules in the US, or India's Digital Personal Data Protection Act, 2023.

This isn't legal advice. But if you'd need to ask your compliance team before emailing a file to a stranger, the same question applies before uploading it.

What good in-house redaction looks like

Whatever tool you choose, look for these five things.

1. Processing stays inside your network. The document is read, checked and redacted on infrastructure you control.
2. Content is removed, not covered. A black shape over text leaves the text in the file. The export should contain nothing that was hidden: no text layer, metadata, comments or old revisions.
3. Detection fits your documents. Client files carry account numbers, IBANs, tax and national ID numbers, plus matter and reference codes in your own formats. You need built-in rules plus your own.
4. A person reviews before anything leaves. Automatic detection makes suggestions. Someone accountable should check them and see the actual final file before it's released.
5. There's a record. For each document: who redacted it, when, how many items in which categories, and the checksum of what was sent. The record itself shouldn't contain the private text.

How Ombly handles it for teams

Ombly for teams runs on your firm's own servers or cloud. Here's how it lines up with the list above:

• Inside your network. The processing workers run without internet access. Documents and their derivatives are encrypted at rest with AES-256-GCM, using keys you hold.
• Removed, not covered. Every exported page is rebuilt from pixels at 300 DPI, with the selected areas painted black. Nothing from the original PDF is carried across.
• Detection that travels, plus your own rules. Card numbers, IBANs and Aadhaar numbers must pass their checksums; US Social Security, UK National Insurance, PAN and IFSC formats are checked; and names, addresses, emails, phone numbers and file paths are suggested too. Teams add their own patterns for matter numbers, other national IDs or internal references.
• Review first. Every suggestion must be accepted or rejected before a document can be finalised, and the final file must be previewed and confirmed before it can be downloaded.
• An audit trail without the secrets. Uploads, reviews, exports and downloads are logged with categories, counts and checksums, never the matched text.

It handles PDF, Word, Excel, PowerPoint, text files and scans, with OCR running locally. Today one administrator signs in and reviews; separate reviewer roles and approval steps are on the roadmap.

A sensible way to start

Pick one document type you redact often, such as KYC packs or statement bundles, and run it through in-house redaction for a few weeks. Measure the time per document and check every output against the original. That tells you more than any feature list.

If you'd like to try that with Ombly on your own infrastructure, book a call. To see how Ombly compares with other options, read how we compare.