The peso is Mexico's official currency, but almost all purchases can be paid in US dollars with change in pesos. Dollars are accepted almost everywhere, however large bills can be difficult to break. It's a good idea to bring along plenty of $1's, $5's, and $10's or use ATMs. If you go on an adventure out of the main tourist areas, take small denominations of pesos. Before traveling to Los Cabos, we suggest you have $100 US in small bills for tips and unexpected expenses, etc.