[header] How to know if you need an international drivers permit for a car rental overseas [title] Call the car rental agency. [step] The easiest way to discover if you need an idp to rent a car overseas is to contact the agency directly. Call or email a representative from the agency you plan on renting a car from. 
The agency can tell you their policy regarding whether or not an idp is needed to rent a car from them. [substeps] Check the law regarding whether an idp is needed to drive in that country.