What does your dog wear regularly?

I have a small dog (Min Pin). She doesn't like collars and I'm not really fond of them either because I feel like a harness is easier on her neck. Anyways would you let your dog wear a harness pretty much 24/7 if it has the dog Id on it? or would you have a separate collar just for the dog id? Since she is a small dog I feel like a collar and harness will be too much for her. What do you think?