The rule that I have is a very simple one: If the work that I do doesn’t have a byline with my name on it, I don’t name the client on my resume. Some clients are very particular about letting the world at large know that they hire freelance writers to do work for them, and they are entitled to a certain level of privacy. Unless one of them specifically told me that it’s all right to mention them by name, I would err on the side of keeping that information confidential.
In our work as freelance writers, we sometimes are privy to confidential information about our clients and their business. In a past life (and that’s what it feels like now), I worked in a number of law firms and I was told from the outset that the quickest and easiest way to get fired from that kind of job is to blab about client information. I’ve carried that policy forward into this career choice, too, and that includes who has hired me to work for them.
I think that most prospective clients are more concerned about what you can do for them, as opposed to who else you have worked for. You can list the types of projects you have worked on without naming names, and that might be the better way to go. If you reveal too much information about your past and current clients, a prospective one will wonder (and for good reason) if you will be discussing their business as well.
When you do think it’s appropriate to list client names on your freelance writer resume?