Employees adopt AI tools whether or not a policy exists, often through free consumer products that retain whatever they are given, a pattern sometimes called shadow AI. A written policy replaces that guesswork with clear rules: which tools are approved, what customer or financial data can never be pasted into a public AI product, and who to ask when a new use case comes up.
The common mistake is writing a policy that blocks everything and getting ignored within a month. A policy that names approved tools, gives a fast path to request a new one and explains the reasoning behind each rule is more likely to be followed than a long list of bans. It should be reviewed at least once a year as new tools and models appear.