How to remove names, emails and phone numbers before pasting text into ChatGPT or Claude

You have an email thread, a case note, or an ordinary block of work text, and you want an AI to help you summarise or rewrite it. It is full of names, emails, phone numbers and maybe an address or two, and every one of those details leaves your machine the moment you paste it. This page shows the manual way to find those details, swap them for placeholders before you paste, and put the real ones back afterward. It works, it needs no tool at all, and with a little practice it takes only a few minutes.

The manual method

Work in a plain text editor or word processor, not the chat window itself, so you can read the whole thing calmly before it goes anywhere.

1. Read the text once from top to bottom. Note every full name, every email address, every phone number and every street address before changing anything.
2. Pick one consistent placeholder for each person, such as [NAME_1], and use that exact placeholder every time that same person is mentioned, including a nickname or a shortened first name, so the AI's reply about "NAME_1" maps back to the right person.
3. Do the same for emails and phone numbers. Watch for the same number written two ways, such as 604-555-0142 next to (604) 555-0142: both are the same person's number and need the same placeholder, or the restore step returns the wrong one.
4. For a street address, decide whether the whole line needs hiding or only the house number and street name; a city and province on their own are usually safe to leave, since they carry little on their own.
5. For a card or account number, check whether it is a real identifying number worth hiding, rather than a generic reference or file number the business already publishes elsewhere.
6. Keep a plain scratch note, on paper or in a second file you never paste anywhere, mapping each placeholder to the real value.
7. Read the masked text once more before sending, looking specifically for a name that appears only once and is easy to miss, or a nickname that does not obviously match the full name you already replaced.
8. When the reply comes back, open your scratch note and substitute each placeholder for its real value by hand, checking each one as you go.

Cost in time: a short email or a two-paragraph note takes about two to four minutes done carefully. A longer document, a case file, or an email thread with several people in it can take fifteen to thirty minutes, because every name and number needs checking for repeats and for a second spelling of the same person.

Where this goes wrong

• A name gets missed because it sits at the start of a sentence and reads as ordinary capitalisation rather than as a person's name.
• The same person's phone number, written two different ways in the same document, ends up behind two different placeholders, so the restore step returns the wrong number in one of the two spots.
• Two people who share a first name get mixed up, and the placeholder for one is pasted back for the other.
• Skipping the final read-through because you are rushed, which is exactly when it matters most, since the client email you are in a hurry to answer is usually the one with the most personal detail in it.

The one-step way

Maskback runs the same steps in one pass, in your own browser tab, with nothing installed and no account. Paste the text, press Redact, read what comes back, send that to the AI, then paste its reply back in to restore the real names and numbers. Try the free version for anything under 2,000 characters a pass, or visit the product page to buy the file, 19.00 USD personal, 79.00 USD team, one purchase, no subscription. A company that wants every desk covered can take the Source and Intranet Licence, all six tools with their source, one purchase.

Detection, by hand or with Maskback, is pattern based. Review the output before you send it, every time.