We recommend bringing enough cash for tipping your porter and your guide as well as a few soles if you need to buy a few other items along the way.  In the first 2 days of the Inca Trail, there are some opportunities to buy snacks from local vendors along the way. They usually sell drinks, snacks, and other essentials like sunscreen and mosquito repellent. There are also a few toilets during the first day that require payment if you decide to use them.