Five things never to paste into an AI

Nearly everything is fine. A letter, a photo of your fridge, a draft of an awkward email, a contract you are about to sign: paste away. The apps are built for that.

Five things are different, because they let someone act as you.

The five

1. Passwords and codes. Any password, any two-factor code, any recovery phrase. No AI needs them to help you, and anything asking for them is the point to stop.
2. Card and bank numbers. It can read a bank letter without the account number. Cover it with a finger in the photo.
3. ID documents. Passport, driving licence, national insurance or social security number. Together with your name and address these are an identity.
4. Other people’s private things. A friend’s medical details, a colleague’s salary, a client’s data. Not yours to paste.
5. Work secrets. Unreleased plans, customer lists, source code your employer owns. Most companies now have a rule about this, and “I did not think” is not a defence.

The test I use: would I email this to a company I have never met? If not, it stays out.

The one setting

By default, most apps use your conversations to improve their models (the AI systems that write the replies). You can switch that off in the settings, usually under data controls or privacy. Do it once. It does not change what the AI can do for you.

If you are unsure what you already pasted

Looking back over this conversation, have I shared anything that looks like a password,
a card or account number, an ID number, or private details about another person? List
anything that matches, quote nothing, and tell me what I should change or delete.

A deleted chat is not a guarantee, but it is better than leaving it there.