Generally, a service fee is automatically added to the bill in most of the tourist hotels and restaurants. If it is not, the average tipping standard is normally 10% of the bill. It is customary to tip bellboys, porters, guides as well as taxi drivers especially if they do a good job. Guides and personal drivers should be tipped between 100-300 rupees per day, depending on the quality of service. Also, you definitely do not tip a volunteer.