Leaving a tip is voluntary and should be done to reward good service, but remember you are not obliged to do so. Tips are not included in the bill and you should not be asked to pay any additional amount for being served. In Tenerife, it is not considered rude not to leave a tip, as it is understood to be voluntary when the professional service provided is good. The standard at bars and restaurants is to leave a tip of 5 to 10% of the bill, depending on how much it adds up to. In taxis, it is common practice to round up the cost of the journey to the nearest unit in the form of a tip.