What personal data to hide before pasting a document into ChatGPT, Claude or Copilot
Before you paste a client document into an AI, it helps to know what data it carries. This is a practical list, and a way not to depend on checking page by page.
The short list
- Identity documents: DNI, NIE, CURP, RFC, CPF, CUIT, NIT, RUT and others.
- Contact details: emails and phone numbers.
- Financial data: card and bank account numbers.
- Names: of people and of companies.
- Form fields: address, case number, date of birth.
Why checking by hand fails
The same data shows up repeated across pages, in different formats, inside tables and footers. Something always slips through on page fourteen. And when there are several documents for one client, you have to hide the same thing the same way in all of them.
How to do it without going page by page
ContextDeck converts the document on your computer and hides, with no setup, ID numbers from 32 countries, emails, phone numbers, cards and bank accounts. You add your clients’ and companies’ names once and they are hidden in every document.
Before you copy, you see what was hidden (marked in the document) and what is still visible, and you can hide or show an item again with one click.
To see how this works on a short text, use the free personal data detector in your browser.
What it does not do by itself
It does not recognise a proper name inside a paragraph. That is why the review before copying is part of the process: it shows you what is still in view, and you hide it by selecting it.
More guides
If you work with contracts, read how to use ChatGPT with client contracts. If you work with bank statements and invoices, read how to anonymize them before using AI.
Frequently asked questions
Is hiding the client’s name enough?
No. The same document usually carries ID numbers, emails, phone numbers and accounts. It is best to hide all of them.
Can I undo something that was hidden by mistake?
Yes. If something hidden was not personal, you show it again before you copy.
How many countries’ ID documents does it recognise?
32 countries. Among the documents it hides with no setup are the RUT, DNI and NIE, CURP and RFC, CPF, CUIT and NIT.
Does this make me compliant with privacy law?
It is not a guarantee of compliance. ContextDeck reduces the risk of exposing personal data when you use AI and keeps a record of what you did. It is not legal advice and does not replace the legal review your own jurisdiction requires.
Keep reading
- Use ChatGPT With Client Contracts Without Exposing Data
- Anonymize Bank Statements Before Using AI
- Free personal data detector (runs in your browser)
- Hide Personal Data Before Using AI: App or Browser Extension?
- ContextDeck for HR teams
ContextDeck reduces the risk of exposing personal data when you use AI and keeps a record of what you did. It is not legal advice and does not replace the legal review your own jurisdiction requires.
Try it on a sample document
Try Pro free for 14 days, no card. You download the Windows app and nothing is uploaded to the internet.
Download for Windows