Originally Posted by
nacho
There are hotels that provide an envelop for tips.
You can't put in into your hotel bill because the whole point for tips is to tip the housekeeper that cleans your room. Also I don't think housekeepers necessarily want IRS to know how much tips they got

While pretty much all tipped employees prefer cash for the reason you stated, I think they would all prefer credit card tip that is reported to the IRS vs. no tip at all.