Can our staff use their own computers?

The case for letting people use personal computers is real: no hardware cost, people prefer their own machine, and it feels flexible. Here is the other side, because it does not usually get laid out before the decision is made.

• Company data ends up on a computer you do not own. When that person leaves, resigns badly, or has their laptop stolen, you have no right to touch it and no way to remove what is on it. For a business with client records, financial data or anything regulated, this is the whole problem in one sentence.
• You cannot require what you cannot manage. Encryption, current patches, working antivirus, a screen lock. On a company machine these are set and verified. On a personal machine you are relying on a request.
• Support gets awkward and expensive. When a personal laptop has a problem, is that your problem? If we fix their machine, we are fixing a computer with family photos, personal tax returns and whatever else on it. If we do not, they cannot work.
• The savings are smaller than they look. A decent business laptop spread across three or four years is a modest monthly figure, and it is deductible, and it comes with a warranty and a standard build that we can replace in an hour.

If you are going to do it anyway, and sometimes there is a genuine reason, do it in the way that limits the damage. Keep the data off the device entirely: work happens in the browser, in Microsoft 365, in the hosted line of business system, with nothing downloaded locally. Require multi-factor authentication without exception. And write down, before anyone starts, what happens to that device when the person leaves.

Phones are a different and more reasonable conversation, because almost everyone reads work email on a personal phone. There we set policy so that company email and files live in a managed area of the phone that we can remove without touching anything personal, which is a decent arrangement for both sides.