The accepted currency in Nainital is the Indian Rupee (INR). It's advisable to exchange currency at authorized banks or exchange bureaus for the best exchange rates. ATMs are widely available in the main town areas, so it's convenient to withdraw cash. Credit cards are accepted at most hotels, restaurants, and larger shops, but it's useful to carry some cash for smaller vendors and local markets. Mobile payment options like Paytm and Google Pay are also becoming increasingly popular in Nainital.