As AI tools become part of ordinary work, a practical question arrives that most small businesses have not thought about deliberately: what should not be put into one. The discussion around this tends to be either dismissive - it is fine, everyone does it - or vague and alarming, and neither helps somebody deciding in the moment whether to paste a document in. A more useful approach is to stop asking whether the tool is safe in general and start asking a different question about the specific information: who does this belong to, and what have we told them we would do with it.
That reframing does most of the work. Information the business owns and could show to an adviser without asking anyone is straightforward: your own figures, your own drafts, your own descriptions of your own problems. Information that belongs to somebody else is different, and it is different regardless of how well the tool behaves. Customer records, employee details, a client's confidential documents, anything covered by a confidentiality agreement, medical or financial details about identifiable people - these were given to the business for a purpose, often with an explicit or implied assurance, and passing them to a third party is a decision about somebody else's information rather than your own convenience.
There is also a category that is simply not worth the argument: passwords, keys, bank details, and anything that would let somebody act as the business. Not because a particular tool is likely to leak them, but because there is no version of this where pasting a credential into a chat box was necessary - the task can always be described without it. The same goes for a document you have not read. Handing over something whose contents you do not know means you cannot know what you have disclosed, and that uncertainty is itself the problem.
For the awkward middle - a real document with a customer's name in it, a spreadsheet with identifiable people in one column - the usual answer is to remove the identifying parts rather than to abandon the task. A tool asked to check a contract does not need the counterparty's name. One asked to analyse sales does not need customer names, only the figures. One asked to draft a reply needs the substance of the complaint, not the address. That takes a minute, keeps almost all of the benefit, and turns a question about a supplier's policies into one the business can answer on its own. It is also worth a short conversation with whoever else works there, since the decision is currently being made many times a day by whoever is at the keyboard, on no stated basis at all.