NO, niet, nein, non ! Buenas cuentas, buenos amigos! Tipping in Barcelona is not expected unlike in America, Great Britain or the Netherlands for instance where tips are a must because waiters practically live from tipping. In Barcelona (and Spain in general) you can be as scroogy as Scrooge himself. Everywhere you go, you’ll be given back the exact change: waiters get paid on a fixed salary each month and benefit from a rather well developed social system compensations.
You can tip waiters in restaurants, bars and clubs, taxi drivers, grooms in hotels (but none of these people expect it). Do not tip anyone else like public agents of any kind, hairdressers, teachers or employees especially in expensive and posh places, they don’t need it and/or they are supposed to give you the best service ever, regardless of what you give them in return.
Well, you obviously tip in Barcelona whenever you feel like it: when the service pleases you, when the food is awesome, when the cab driver makes you laugh, when the waiter/waitress is nice, when you want to impress somebody (anybody for any reason)…
Tips in Barcelona are left only when you pay cash. If you pay with a credit card, there is no second line on the receipt for tips.
It cannot be denied that tipping in Barcelona is pleasant whenever tips are not expected. There is nothing like seeing a bright smile suddenly expand on somebody’s lips and gratefulness appear in their eyes. Then, you can go home on a pink cloud for your good action. Besides, if the service you have just received is normal or bad, why should you tip?
Catalan people will appreciate any tip you leave without feeling insulted, from 10cents to any amount you like. Tips of 1 or 2€ are already very good tips in Barcelona. In certain places waiters ring a bell anytime they receive a tip (as in Síncopa) and I sometimes tip them with a simple “keep the change!” just to hear the bell.
Tipping in Barcelona is a left to your appreciation. Make good use of it!