Concierges don't expect concierge tipping. Gratuities are part of the many services hotels provide.
However, if guests want to show their appreciation, they can. For a job well done, tt is appropriate to slip money in an envelope with a brief thank you note to the concierge or the concierge staff.
Tipping is optional for a simple advice. Giving you directions is part of the job. Looking up the phone number of a restaurant and making a reservation is standard practice. But, tipping $2 to $5 for global daily assistance is appropriate and in line with hotel tipping guidelines.
You should tip $5 to $10 for help with hard-to-get dinner reservations or for last-minute or sold-out theater tickets. Tip $10 for booking various tours or for a shopping, cultural and/or night-out extravaganza. A $20 tip is reasonable when the role of a concierge is really put into action when s/he makes plans for a full day, including travel arrangements, reservations and tickets. Tip more for more elaborated assistance.
Tipping can be done when the service is provided or at the end of a stay. Make sure you keep track of all your dealings with the concierge or the concierge staff and be honest and fair.
You may also consider tipping the concierge upon arrival while introducing yourself. A concierge will try hard to do the impossible, especially if s/he knows who you are and has been thanked in advance.
Leave a tip for the particular concierge who helped you with well appreciated corporate concierge services. If s/he is not available or cannot be found, leave your tip and your business card in an envelope. If s/he cares to thank you, s/he'll know how to reach you. S/he will also remember you if and when you return to the hotel.
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