I utilize the standard 24 hour policy, but there are always exceptions. If my 3:00am client sent me a message 24 hours in advance (on Sunday BEFORE 3:00am) telling me she was sick and doesn’t think she’ll be in, I’d find it very hard to believe that she would know that on Sunday morning.
While I strongly use 24 hour notice, I also inform my clients that they can text me whenever they need, to cancel their appoinment. Hey life happens and I’m not so hard-nose not to recognize the fact after 16 years. I strongly encourage a “Common Courtsey” policy which I’ve rarely had a problem with.
If I have a client that frequently cancels (with little or no notice), I will tell her after the second time, that if this continues they will be charged from this point on and that I will no longer use my “CC” rule. Weirdly enough I find the clients that are chronically repeat offenders are my Doctors, Attorneys, Dentist (i.e. the people who also have a 24 hour policy).