I agree with @JamesB I prefer to be told in advance, before scheduling the next appointment. Everything has gone up and you need cover your expenses and make ends meet. I actually manage pricing in career and as long as a client thinks they are receiving value, most clients should be fine. I've had providers tell me their rates were increasing as of some date in the future and I, personally, was ok with it. I appreciated the head's up as I tend to pay in cash and want to make sure I have enough to cover fees and tips.